Southampton is the largest city in the ceremonial county of Hampshire, England. It is 69 miles (111 km) south-west of London and 15 miles (24 km) west north-west of Portsmouth. Southampton is a major port and the closest city to the New Forest. It lies at the northernmost point of Southampton Water at the confluence of the Rivers Test and Itchen, with the River Hamble joining to the south of the urban area. The city, which is a unitary authority, has an estimated population of 253,651. The city's name is sometimes abbreviated in writing to "So'ton" or "Soton", and a resident of Southampton is called a Sotonian.

Significant employers in the city include Southampton City Council, the University of Southampton, Solent University, Southampton Airport, Ordnance Survey, BBC South, the NHS, ABP and Carnival UK. Southampton is noted for its association with the RMS Titanic, the Spitfire and more generally in the World War II narrative as one of the departure points for D-Day, and more recently as the home port of a number of the largest cruise ships in the world. Southampton has a large shopping centre and retail park, Westquay. In 2014, the city council approved a neighbouring followup Westquay South which opened in 2016–2017.

In the 2001 census Southampton and Portsmouth were recorded as being parts of separate urban areas; however by the time of the 2011 census they had merged apolitically to become the sixth-largest built-up area in England with a population of 855,569. This built-up area is part of the metropolitan area known as South Hampshire, which is also known as Solent City, particularly in the media when discussing local governance organisational changes. With a population of over 1.5 million this makes the region one of the United Kingdom's most populous metropolitan areas.

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.

Madeira, officially the Autonomous Region of Madeira, is one of the two autonomous regions of Portugal (along with the Azores). It is an archipelago situated in the north Atlantic Ocean, southwest of Portugal. Its total population was estimated in 2011 at 267,785. The capital of Madeira is Funchal, which is located on the main island's south coast.

The archipelago is just under 400 kilometres (250 mi) north of Tenerife, Canary Islands. Bermuda and Madeira, a few time zones apart, are the only land in the Atlantic on the 32nd parallel north. It includes the islands of Madeira, Porto Santo, and the Desertas, administered together with the separate archipelago of the Savage Islands. The region has political and administrative autonomy through the Administrative Political Statue of the Autonomous Region of Madeiraprovided for in the Portuguese Constitution. The autonomous region is an integral part of the European Union as an outermost region.