Portugal–Spain border disputed between the two countries for two hundred years. A microstate existed previously on the border called Couto Misto. Districts on the Portuguese side of the border from North to South: Provinces on the Spanish side of the border from North to South: Portugal and Spain signed the Schengen Agreement in June 1991 which came into effect on 26 March 1995, making Portugal and Spain part of the Schengen area and thus the border then became an Open border. Portugal has since reintroduced border checks several times along the border with Spain, during the UEFA Euro 2004 championships, during the
Denmark–Sweden border was still a country although under practical control by Germany). The Nordic Passport Union of 1958 removed passport checks at the border. However, custom checks remained in force between Denmark and other Nordic countries until the Schengen acquis of 2001. There was no land border with Denmark before July 2000 when the Øresund Bridge was opened, which had relaxed customs checks from the start. With the European migrant crisis, Sweden re-introduced stricter border controls in November 2015. Since 4 January 2016, Sweden has required carriers to perform identity checks on the Danish side of the Denmark–Sweden border, while still keeping