The region's largest city stands on an isthmus with two deep bays to seaward and a fine natural Inner Harbour to the west. It naturally attracted the attention of European colonial powers as early as the first quarter of the 17th century, changing hands repeatedly among the Portuguese, the Dutch, the French and the British in a series of side-shows to the European wars of the 17th and 18th centuries, before finally falling to a British fleet in 1795. It remained one of the British Empire's most important ports in Asia, and from 1941-45 was the headquarters of the Allied Southeast Asia commander, Lord Louis Mountbatten. Other distinguished British military men to have sojourned here include Sir Arthur Wellesley (later the Duke of Wellington), who recuperated here in 1799 from fever caught while campaigning against the French and their allies in southern India. In the middle of the Inner Harbour, connected to the isthmus by a narrow causeway, is Powder Island, once a gunpowder magazine for the Royal Navy, but now occupied by the Sri Lankan defence force.

Fort Frederick
The northeast-pointing promontory which separates Dutch Bay from Back Bay was fortified first by the Portuguese, then by their successors and finally by the British, who named it Fort Frederick. At the tip of the promontory is Swami Rock, where a Hindu temple stood until being demolished by the Portuguese.

Trincomalee beaches
Uppuveli is the most conveniently located beach for those staying in Trincomalee, only 6km (4 miles) north of the city centre and accessible by taxi or three-wheeler. Nilaveli is a 4km (2.5-mile) stretch of beach which starts about 16km (10 miles) north of Trincomalee.