The Spanish outposts of Ceuta and Melilla in North Africa, which have the European Union’s only land borders with Africa, are tempting launch pads for clandestine immigration to continental Europe. Reinforced borders Ceuta, a former Roman colony with a population of 84,000, measures about 18 square kilometres (seven square miles) and lies just across the Strait of Gibraltar from Spain. It was captured by the Arabs and the Portuguese and has been under Spanish sovereignty since 1640. Melilla, measuring about 200 square kilometres, is perched on the eastern edge of Morocco’s Mediterranean coast, and has been under Spanish control since 1497. It has a diverse population of about 87,000, of which around half are Muslims, and thousands of Moroccans go there to work and shop every day. The two territories are protected by fences fortified with barbed wire, video cameras and watchtowers. In the past, migrants have died or been injured trying to breach the barriers. Disputed territory Both enclaves were conquered as part of a strategy by Catholic kings of establishing advance posts of Christendom on the African continent following the expulsion of Moors and Jews from Spain in 1492. Claimed by Morocco, the two cities have long been a flashpoint in diplomatic relations between Madrid and Rabat, with Madrid insisting that both are integral parts of Spain. Both port cities have developed as military and trade centres linking Africa to Europe, and since the 1990s have enjoyed a status similar to other autonomous areas such as the Basque region and Catalonia.