Tarragona is a port city located in northeast Spain on the Costa Daurada by the Mediterranean Sea. Founded before the 5th century BC, it is the capital of the Province of Tarragona, and part of Tarragonès and Catalonia. Geographically, it is bordered on the north by the Province of Barcelona and the Province of Lleida. The city has a population of 201,199 (2014).

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.