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.

Tunisia (officially the Republic of Tunisia) is a country in the Maghreb region of North Africa, covering 165,000 square kilometres (64,000 square miles). Its northernmost point, Cape Angela, is the northernmost point on the African continent. It is bordered by Algeria to the west and southwest, Libya to the southeast, and the Mediterranean Sea to the north and east. Tunisia's population was 11.435 million in 2017. Tunisia's name is derived from its capital city, Tunis, which is located on its northeast coast.

Sicily is the largest island in the Mediterranean Sea and one of the 20 regions of Italy. It is one of the five Italian autonomous regions, in Southern Italy along with surrounding minor islands, officially referred to as Regione Siciliana.

Sicily is located in the central Mediterranean Sea, south of the Italian Peninsula, from which it is separated by the narrow Strait of Messina. Its most prominent landmark is Mount Etna, the tallest active volcano in Europe, and one of the most active in the world, currently 3,329 m (10,922 ft) high. The island has a typical Mediterranean climate.

The earliest archaeological evidence of human activity on the island dates from as early as 12,000 BC. By around 750 BC, Sicily had three Phoenician and a dozen Greek colonies and, for the next 600 years, it was the site of the Sicilian Wars and the Punic Wars. After the fall of the Roman Empire in the 5th century AD, Sicily was ruled during the Early Middle Ages by the Vandals, the Ostrogoths, the Byzantine Empire, and the Emirate of Sicily. The Norman conquest of southern Italy led to the creation of the Kingdom of Sicily, which was subsequently ruled by the Hohenstaufen, the Capetian House of Anjou, Spain, and the House of Habsburg. It was finally unified under the House of Bourbon with the Kingdom of Naples as the Kingdom of the Two Sicilies. It became part of Italy in 1860 following the Expedition of the Thousand, a revolt led by Giuseppe Garibaldi during the Italian unification, and a plebiscite. Sicily was given special status as an autonomous region on 15th May 1946, 18 days before the Italian constitutional referendum of 1946. Albeit, much of the autonomy still remains unapplied, especially financial autonomy, because the autonomy-activating laws have been deferred to be approved by the parithetic committee (50% Italian State, 50% Regione Siciliana), since 1946.

Sicily has a rich and unique culture, especially with regard to the arts, music, literature, cuisine, and architecture. It is also home to important archaeological and ancient sites, such as the Necropolis of Pantalica, the Valley of the Temples, Erice and Selinunte.

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.

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.