Estonia lies on the eastern shores of the Baltic Sea immediately across the Gulf of Finland from Finland on the level northwestern part of the rising East European platform between 57.3° and 59.5° N and 21.5° and 28.1° E. Average elevation reaches only 50 metres (164 ft) and the country's highest point is the Suur Munamägi in the southeast at 318 metres (1,043 ft). There is 3,794 kilometres (2,357 mi) of coastline marked by numerous bays, straits, and inlets. The number of islands and islets is estimated at some 2,355 (including those in lakes). Two of them are large enough to constitute separate counties: Saaremaa and Hiiumaa. A small, recent cluster of meteorite craters, the largest of which is called Kaali is found on Saaremaa, Estonia.

What body of water borders Estonia?