Estonia, a country in Northern Europe, borders the Baltic Sea and Gulf of Finland. Including more than 1,500 islands, its diverse terrain spans rocky beaches, old-growth forest and many lakes. Formerly part of the Soviet Union, it's dotted with castles, churches and hilltop fortresses. The capital, Tallinn, is known for its preserved Old Town, museums and the 314m-high Tallinn TV Tower, which has an observation deck.