In 1995 , the Warsaw Metro opened with a single line . A second line was opened in March 2015 . With the entry of Poland into the European Union in 2004 , Warsaw is currently experiencing the largest economic boom of its history . The opening fixture of UEFA Euro 2012 took place in Warsaw , a game in which Poland drew 1 – 1 with Greece . Warsaw was the host city for the 2013 United Nations Climate Change Conference and for the 2016 NATO Summit
2016 NATO Summit
2016 Warsaw summit
Warsaw