The Trakai Island Castle is the single most visited sight in Lithuania outside of Vilnius, and the photographs don't lie — the red-brick Gothic castle rising from Lake Galvė, connected to the shore by a wooden footbridge, is genuinely spectacular. Originally built in the 14th century as the main fortress of the Grand Duchy of Lithuania, it fell into ruin after the capital moved to Vilnius and was extensively restored in the 20th century, primarily between 1951 and 1987.
The interior now houses a history museum covering the Grand Duchy period, with collections of armour, coins, jewellery, and maps from the era when the Grand Duchy stretched from the Baltic to the Black Sea. The views from the towers are excellent — the lake system around Trakai spreads in all directions, and on clear days the Vilnius TV tower is visible on the horizon. The castle is best seen from the surrounding lakes, particularly from the south shore across Lake Galvė, where the full reflection is visible.