Calais border barrier

A border barrier, border fence or border wall is a separation barrier that runs along or near an international border. Such barriers are typically constructed for border control purposes such as curbing illegal immigration, human trafficking, and smuggling. Some such barriers are constructed for defence or security reasons. In cases of a disputed or unclear border, erecting a barrier can serve as a de facto unilateral consolidation of a territorial claim that can supersede formal delimitation. A border barrier does not usually indicate the location of the actual border, and is usually constructed unilaterally by a country, without the agreement or cooperation of the other country.

The Channel Tunnel, also known as the Chunnel, is a 50.46-kilometre (31.35 mi) underwater railway tunnel that connects Folkestone with Coquelles beneath the English Channel at the Strait of Dover. It is the only fixed link between the island of Great Britain and the European mainland. At its lowest point, it is 75 metres (246 ft) deep below the sea bed and 115 metres (377 ft) below sea level. At 37.9 kilometres (23.5 mi), it has the longest underwater section of any tunnel in the world, and is the third longest railway tunnel in the world. The speed limit for trains through the tunnel is 160 kilometres per hour (99 mph). The tunnel is owned and operated by the company Getlink, formerly "Groupe Eurotunnel".

Calais is a port city in the Pas-de-Calais department, of which it is a subprefecture. Although Calais is by far the largest city in Pas-de-Calais, the department's prefecture is its third-largest city of Arras. The population of the city proper is 72,929; that of the urban area is 149,673 (2018). Calais overlooks the Strait of Dover, the narrowest point in the English Channel, which is only 34 km (21 mi) wide here, and is the closest French town to England. The White Cliffs of Dover can easily be seen on a clear day from Calais. Calais is a major port for ferries between France and England, and since 1994, the Channel Tunnel has linked nearby Coquelles to Folkestone by rail.

The Calais Jungle was a refugee and immigrant encampment in the vicinity of Calais, France that existed from January 2015 to October 2016. There had been other camps known as "jungles" in previous years, but this particular shanty town drew global media attention during the peak of the European migrant crisis in 2015, when its population grew rapidly. Migrants stayed at the camp while they attempted to enter the United Kingdom, or while they waited for their French asylum claims to be processed.