Sveaborg
a fortress in Finland; sometimes called "the Gibraltar of the North," protects the harbor and town of Helsingfors, from which it is 3 miles distant. The fortifications were planned and first prepared by Count Ehrensvärd SVEABORG in 1849, and there are an arsenal, docks, slips, and a monument to the "father" of the fortress. The fortifications were betrayed into the hands of the Russians by the Swedish commandant in 1808. It was captured by Finnish forces after the Russian revolution of 1917. Pop. about 1,000.