Abu Dhabi is the capital and the second most populous city of the United Arab Emirates (the most populous being Dubai), and also capital of the Emirate of Abu Dhabi, the largest of the UAE's seven emirates. Abu Dhabi lies on a T-shaped island jutting into the Persian Gulf from the central western coast. The city of Abu Dhabi has an estimated population of 1.8 million in 2016.

Abu Dhabi houses federal government offices, is the seat of the United Arab Emirates Government, home to the Abu Dhabi Emiri Family and the President of the UAE, who is from this family. Abu Dhabi's rapid development and urbanisation, coupled with the relatively high average income of its population, has transformed the city into a large and advanced metropolis. Today the city is the country's centre of political and industrial activities, and a major cultural and commercial centre, due to its position as the capital. Abu Dhabi accounts for about two-thirds of the roughly $400-billion United Arab Emirates economy.

Muscat is the capital and largest city of Oman. It is the seat of the Governorate of Muscat. According to the National Centre for Statistics and Information (NCSI), the total population of Muscat Governorate reached 1.4 million as of September 2018. The metropolitan area spans approximately 3,500 km2 (1,400 sq mi) and includes six provinces called wilayats. Known since the early 1st century CE as an important trading port between the west and the east, Muscat was ruled by various indigenous tribes as well as foreign powers such as the Persians, the Portuguese Empire, the Iberian Union and the Ottoman Empire at various points in its history. A regional military power in the 18th century, Muscat's influence extended as far as East Africa and Zanzibar. As an important port-town in the Gulf of Oman, Muscat attracted foreign tradesmen and settlers such as the Persians and the Balochis. Since the ascension of Qaboos bin Said as Sultan of Oman in 1970, Muscat has experienced rapid infrastructural development that has led to the growth of a vibrant economy and a multi-ethnic society.

Aqaba is the only coastal city in Jordan and the largest and most populous city on the Gulf of Aqaba. Situated in southernmost Jordan, Aqaba is the administrative centre of the Aqaba Governorate. The city had a population of 148,398 in 2015 and a land area of 375 square kilometres (144.8 sq mi). Today, Aqaba plays a major role in the development of the Jordanian economy, through the vibrant trade and tourism sectors. The Port of Aqaba also serves other countries in the region.

Aqaba's strategic location at the northeastern tip of the Red Sea between the continents of Asia and Africa, has made its port important over the course of thousands of years.

The Suez Canal is a sea-level waterway in Egypt, connecting the Mediterranean Sea to the Red Sea through the Isthmus of Suez. Constructed by the Suez Canal Company between 1859 and 1869, it was officially opened on 17 November 1869. The canal offers watercraft a shorter journey between the North Atlantic and northern Indian Oceans via the Mediterranean and Red Seas by avoiding the South Atlantic and southern Indian Oceans, reducing the journey by approximately 6,000 kilometres (3,700 mi). It extends from the northern terminus of Port Said to the southern terminus of Port Tewfik at the city of Suez. Its length is 193.30 km (120.11 mi), including its northern and southern access channels. In 2012, 17,225 vessels traversed the canal (average 47 per day).

The Suez Canal is a sea-level waterway in Egypt, connecting the Mediterranean Sea to the Red Sea through the Isthmus of Suez. Constructed by the Suez Canal Company between 1859 and 1869, it was officially opened on 17 November 1869. The canal offers watercraft a shorter journey between the North Atlantic and northern Indian Oceans via the Mediterranean and Red Seas by avoiding the South Atlantic and southern Indian Oceans, reducing the journey by approximately 6,000 kilometres (3,700 mi). It extends from the northern terminus of Port Said to the southern terminus of Port Tewfik at the city of Suez. Its length is 193.30 km (120.11 mi), including its northern and southern access channels. In 2012, 17,225 vessels traversed the canal (average 47 per day).

the chief port of Egypt; population 4,084,700 (est. 2006). Founded in 332 bc by Alexander the Great, it was a major center of Hellenistic culture, renowned for its library and for the Pharos lighthouse.

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.

 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.