Rome is the capital city and a special comune of Italy (named Comune di Roma Capitale). Rome also serves as the capital of the Lazio region. With 2,872,800 residents in 1,285 km2(496.1 sq mi), it is also the country's most populated comune. It is the fourth-most populous city in the European Union by population within city limits. It is the centre of the Metropolitan City of Rome, which has a population of 4,355,725 residents, thus making it the most populous metropolitan city in Italy. Rome is located in the central-western portion of the Italian Peninsula, within Lazio (Latium), along the shores of the Tiber. The Vatican City (the smallest country in the world) is an independent country inside the city boundaries of Rome, the only existing example of a country within a city: for this reason Rome has been often defined as capital of two states.

Rome's history spans 28 centuries. While Roman mythology dates the founding of Rome at around 753 BC, the site has been inhabited for much longer, making it one of the oldest continuously occupied sites in Europe. The city's early population originated from a mix of Latins, Etruscans, and Sabines. Eventually, the city successively became the capital of the Roman Kingdom, the Roman Republic and the Roman Empire, and is regarded as the birthplace of Western civilization and by some as the first ever metropolis. It was first called The Eternal City (Latin: Urbs Aeterna; Italian: La Città Eterna) by the Roman poet Tibullus in the 1st century BC, and the expression was also taken up by Ovid, Virgil, and Livy. Rome is also called the "Caput Mundi" (Capital of the World). After the fall of the Western Empire, which marked the beginning of the Middle Ages, Rome slowly fell under the political control of the Papacy, which had settled in the city since the 1st century AD, until in the 8th century it became the capital of the Papal States, which lasted until 1870. Beginning with the Renaissance, almost all the popes since Nicholas V (1447–1455) pursued over four hundred years a coherent architectural and urban programme aimed at making the city the artistic and cultural centre of the world. In this way, Rome became first one of the major centres of the Italian Renaissance, and then the birthplace of both the Baroque style and Neoclassicism. Famous artists, painters, sculptors and architects made Rome the centre of their activity, creating masterpieces throughout the city. In 1871, Rome became the capital of the Kingdom of Italy, which, in 1946, became the Italian Republic.

Rome has the status of a global city. In 2016, Rome ranked as the 14th-most-visited city in the world, 3rd most visited in the European Union, and the most popular tourist attraction in Italy. Its historic centre is listed by UNESCO as a World Heritage Site. The famous Vatican Museums are among the world's most visited museums while the Colosseum was the most popular tourist attraction in world with 7.4 million visitors in 2018. Host city for the 1960 Summer Olympics, Rome is the seat of several specialized agencies of the United Nations, such as the Food and Agriculture Organization (FAO), the World Food Programme (WFP) and the International Fund for Agricultural Development (IFAD). The city also hosts the Secretariat of the Parliamentary Assembly of the Union for the Mediterranean (UfM) as well as the headquarters of many international business companies such as Eni, Enel, TIM, Leonardo S.p.A., and national and international banks such as Unicredit and BNL. Its business district, called EUR, is the base of many companies involved in the oil industry, the pharmaceutical industry, and financial services. Rome is also an important fashion and design centre thanks to renowned international brands centered in the city. Rome's Cinecittà Studios have been the set of many Academy Award–winning movies.

Naples is the regional capital of Campania and the third-largest municipality in Italyafter Rome and Milan. In 2017, around 967,069 people lived within the city's administrative limits while its province-level municipality has a population of 3,115,320 residents. Its continuously built-up metropolitan area (that stretches beyond the boundaries of the Metropolitan City of Naples) is the second or third largest metropolitan area in Italy and one of the most densely populated cities in Europe.

First settled by Greeks in the second millennium BC, Naples is one of the oldest continuously inhabited urban areas in the world. In the ninth century BC, a colony known as Parthenope or Παρθενόπη was established on the Island of Megaride, later refounded as Neápolis in the sixth century BC. The city was an important part of Magna Graecia, played a major role in the merging of Greek and Roman society and a significant cultural centre under the Romans. It served as the capital of the Duchy of Naples (661–1139), then of the Kingdom of Naples (1282–1816) and finally of the Two Sicilies until the unification of Italy in 1861.

Between 1925 and 1936, Naples was expanded and upgraded by Benito Mussolini's government but subsequently sustained severe damage from Allied bombing during World War II, which led to extensive post-1945 reconstruction work. Naples has experienced significant economic growth in recent decades, helped by the construction of the Centro Direzionale business district and an advanced transportation network, which includes the Alta Velocità high-speed rail link to Rome and Salerno and an expanded subway network. Naples is the third-largest urban economy in Italy, after Milan and Rome. The Port of Naples is one of the most important in Europe and home of the Allied Joint Force Command Naples, the NATO body that oversees North Africa, the Sahel and Middle East.

Naples' historic city centre is the largest in Europe and a UNESCO World Heritage Site, with a wide range of culturally and historically significant sites nearby, including the Palace of Caserta and the Roman ruins of Pompeii and Herculaneum. Naples is also known for its natural beauties such as Posillipo, Phlegraean Fields, Nisida, and Vesuvius.

Neapolitan cuisine is synonymous with pizza – which originated in the city – but it also includes many lesser-known dishes; Naples has the greatest number of accredited stars from the Michelin Guide of any Italian city.

The best-known sports team in Naples is the Serie A club S.S.C. Napoli, two-time Italian champions who play at the San Paolo Stadium in the southwest of the city, in the Fuorigrotta quarter.

Livorno is a port city on the Ligurian Sea on the western coast of Tuscany, Italy. It is the capital of the Province of Livorno, having a population of 158,493 residents in December 2017. It has traditionally been known in English as Leghorn.

The origins of Livorno are controversial, although the place was inhabited since the Neolithic Age as shown by worked bones, pieces of copper and ceramic found on the Livorno Hills in a cave between Ardenza and Montenero. The construction of the Via Aurelia coincided with the occupation of the region by the Romans, who left traces of their presence in the toponyms and ruins of towers. The natural cove called Liburna, later transformed into Livorna, before becoming Livorno, is a reference to the type of ship, the liburna, used by Roman navy. Others ancient toponyms include: Salviano (Salvius), Antignano (Ante ignem) which was the place situated before Ardenza (Ardentia) where were the beacons for the ships directed to Porto Pisano.

The name Livorna is mentioned for the first time in 1017 as a small coastal village, the port and the remains of a Roman tower. In 1077, a tower was built by Matilda of Tuscany. The Republic of Pisa owned Livorno from 1103 and built a quadrangular Fort called Quadratura dei Pisani ("Quarter of the Pisans") to defend the port. Porto Pisano was destroyed after the crushing defeat of the Pisan fleet in the Battle of Meloria in 1284. In 1399, Pisa sold Livorno to the Visconti of Milan, in 1405 it was sold to the Republic of Genoa and on 28 August 1421 it was bought by the Republic of Florence.

Between 1427 and 1429, a census counted 118 families in Livorno, including 423 persons. Monks, Jews, military personnel, and the homeless were not included in the census. The only remainder of medieval Livorno is a fragment of two towers and a wall, located inside the Fortezza Vecchia.

Nice  is the seventh most populous urban area in France and the capital of the Alpes-Maritimes département. The metropolitan area of Nice extends beyond the administrative city limits, with a population of about 1 million on an area of 721 km2 (278 sq mi). Located in the French Riviera, on the south east coast of France on the Mediterranean Sea, at the foot of the Alps, Nice is the second-largest French city on the Mediterranean coast and the second-largest city in the Provence-Alpes-Côte d'Azur region after Marseille. Nice is approximately 13 kilometres (8.1 mi) from the principality of Monaco and 30 kilometres (19 mi) from the French-Italian border. Nice's airport serves as a gateway to the region.

The city is nicknamed Nice la Belle (Nissa La Bella in Niçard), which means Nice the Beautiful, which is also the title of the unofficial anthem of Nice, written by Menica Rondelly in 1912.

The area of today's Nice contains Terra Amata, an archaeological site which displays evidence of a very early use of fire. Around 350 BC, Greeks of Marseille founded a permanent settlement and called it Nikaia, after Nike, the goddess of victory. Through the ages, the town has changed hands many times. Its strategic location and port significantly contributed to its maritime strength. For centuries it was a dominion of Savoy, and was then part of France between 1792 and 1815, when it was returned to Piedmont-Sardinia until its re-annexation by France in 1860.

The natural environment of the Nice area and its mild Mediterranean climate came to the attention of the English upper classes in the second half of the 18th century, when an increasing number of aristocratic families took to spending their winters there. The city's main seaside promenade, the Promenade des Anglais ("Walkway of the English") owes its name to visitors to the resort. The clear air and soft light have particularly appealed to notable painters, such as Marc Chagall, Henri Matisse, Niki de Saint Phalle and Arman. Their work is commemorated in many of the city's museums, including Musée Marc Chagall, Musée Matisse and Musée des Beaux-Arts. Nice has the second largest hotel capacity in the country and it is one of its most visited cities, receiving 4 million tourists every year. It also has the third busiest airport in France, after the two main Parisian ones. It is the historical capital city of the County of Nice(Comté de Nice).

Marseille is the second-largest city of France. The main city of the historical province of Provence, it nowadays is the prefecture of the department of Bouches-du-Rhône and region of Provence-Alpes-Côte d'Azur. It is located on France's south coast near the mouth of the Rhône river. The city covers an area of 241 km2 (93 sq mi) and had a population of 852,516 in 2012. Its metropolitan area, which extends over 3,173 km2 (1,225 sq mi) is the third-largest in France after Paris and Lyon, with a population of 1,831,500 as of 2010.

 Known to the ancient Greeks and Romans as Massalia, Marseille was an important European trading centre and remains the main commercial port of the French Republic. Marseille is now France's largest city on the Mediterranean coast and the largest port for commerce, freight and cruise ships. The city was European Capital of Culture in 2013 and European Capital of Sport in 2017; it hosted matches at the 1998 World Cup and Euro 2016. It is home to Aix-Marseille University.

 Barcelona is a city in Spain. It is the capital and largest city of Catalonia, as well as the second most populous municipality of Spain. With a population of 1.6 million within city limits, its urban area extends to numerous neighbouring municipalities within the Province of Barcelona and is home to around 4.8 million people, making it the sixth most populous urban area in the European Union after Paris, London, Madrid, the Ruhr area and Milan. It is one of the largest metropolises on the Mediterranean Sea, located on the coast between the mouths of the rivers Llobregat and Besòs, and bounded to the west by the Serra de Collserola mountain range, the tallest peak of which is 512 metres (1,680 feet) high.

Founded as a Roman city, in the Middle Ages Barcelona became the capital of the County of Barcelona. After merging with the Kingdom of Aragon, Barcelona continued to be an important city in the Crown of Aragon as an economic and administrative centre of this Crown and the capital of the Principality of Catalonia. Barcelona has a rich cultural heritage and is today an important cultural centre and a major tourist destination. Particularly renowned are the architectural works of Antoni Gaudí and Lluís Domènech i Montaner, which have been designated UNESCO World Heritage Sites. The headquarters of the Union for the Mediterranean are located in Barcelona. The city is known for hosting the 1992 Summer Olympics as well as world-class conferences and expositions and also many international sport tournaments.

Barcelona is one of the world's leading tourist, economic, trade fair and cultural centres, and its influence in commerce, education, entertainment, media, fashion, science, and the arts all contribute to its status as one of the world's major global cities. It is a major cultural and economic centre in southwestern Europe, 24th in the world (before Zürich, after Frankfurt) and a financial centre. In 2008 it was the fourth most economically powerful city by GDP in the European Union and 35th in the world with GDP amounting to €177 billion. In 2012 Barcelona had a GDP of $170 billion; and it was leading Spain in employment rate in that moment.

In 2009 the city was ranked Europe's third and one of the world's most successful as a city brand. In the same year the city was ranked Europe's fourth best city for business and fastest improving European city, with growth improved by 17% per year, and the city has been experiencing strong and renewed growth for the past three years. Since 2011 Barcelona has been a leading smart city in Europe. Barcelona is a transport hub, with the Port of Barcelona being one of Europe's principal seaports and busiest European passenger port, an international airport, Barcelona–El Prat Airport, which handles over 50 million passengers per year, an extensive motorway network, and a high-speed rail line with a link to France and the rest of Europe.

Mallorca is the largest island in the Balearic Islands, which are part of Spain and located in the Mediterranean. The native language, as on the rest of the Balearic Islands, is Catalan, which is co-official with Spanish.

The capital of the island, Palma, is also the capital of the autonomous community of the Balearic Islands. The Balearic Islands have been an autonomous region of Spain since 1983. There are two small islands off the coast of Mallorca: Cabrera (southeast of Palma) and Dragonera (west of Palma). The anthem of Mallorca is "La Balanguera".

Like the other Balearic Islands of Menorca, Ibiza and Formentera, the island is an extremely popular holiday destination, particularly for tourists from Germany and the United Kingdom. The international airport, Palma de Mallorca Airport, is one of the busiest in Spain; it was used by 28.0 million passengers in 2017, increasing every year since 2012.

The name derives from Classical Latin insula maior, "larger island". Later, in Medieval Latin, this became Maiorica, "the larger one", in comparison to Menorca, "the smaller one".

Gibraltar  is a British Overseas Territory located at the southern tip of the Iberian Peninsula. It has an area of 6.7 km2 (2.6 sq mi) and is bordered to the north by Spain. The landscape is dominated by the Rock of Gibraltar at the foot of which is a densely populated town area, home to over 30,000 people, primarily Gibraltarians. It shares a maritime border with Morocco.

In 1704, Anglo-Dutch forces captured Gibraltar from Spain during the War of the Spanish Succession on behalf of the Habsburg claim to the Spanish throne. The territory was ceded to Great Britain in perpetuity under the Treaty of Utrechtin 1713. During World War II it was an important base for the Royal Navy as it controlled the entrance and exit to the Mediterranean Sea, which is only 8 miles (13 km) wide at this naval choke point. It remains strategically important, with half the world's seaborne trade passing through the strait. Today Gibraltar's economy is based largely on tourism, online gambling, financial services and cargo ship refuelling.

The sovereignty of Gibraltar is a point of contention in Anglo-Spanish relations because Spain asserts a claim to the territory. Gibraltarians rejected proposals for Spanish sovereignty in a 1967 referendum and, in a 2002 referendum, the idea of shared sovereignty was also rejected.

Lisbon is the capital and the largest city of Portugal, with an estimated population of 505,526 within its administrative limits in an area of 100.05 km2. Its urban area extends beyond the city's administrative limits with a population of around 2.8 million people, being the 11th-most populous urban area in the European Union. About 3 million people live in the Lisbon Metropolitan Area (which represents approximately 27% of the country's population). It is mainland Europe's westernmost capital city and the only one along the Atlantic coast. Lisbon lies in the western Iberian Peninsula on the Atlantic Ocean and the River Tagus. The westernmost areas of its metro area form the westernmost point of Continental Europe, which is known as Cabo da Roca, located in the Sintra Mountains.