Which European country's flag has a white-blue-red horizontal tricolour with a coat of arms featuring a double cross on three hills? Slovakia. Its flag combines white, blue and red horizontal stripes with Slovakia's coat of arms near the hoist.
The shield shows a silver double cross standing on three blue hills. The cross is associated with Christian and Byzantine traditions, while the three hills are traditionally identified as the Tatra, Fatra and Mátra ranges. The design draws on Slovak historical and national symbolism, especially the colours used by Slovak national movements in the 19th century.
Slovakia adopted its present state flag on 1 September 1992, shortly before becoming independent on 1 January 1993 after the peaceful dissolution of Czechoslovakia. The coat of arms is essential to the identification: without it, the white-blue-red tricolour can resemble the flags of Russia or Slovenia.
Slovenia is the most likely confusion because it also uses a white-blue-red horizontal tricolour and a shield near the hoist. Slovenia's shield depicts Mount Triglav, stars and waves, whereas Slovakia's unmistakable emblem contains the double cross on three hills.