There is dolphin and whale watching available from most of the guest houses on Uppaveli beach (high season only).
Fort Fredrick is an old Dutch fort dating back to 1665 located on a peninsula North East of the town center. It has a long and storied history and was the site of battles involving (at different times) the Portuguese, Dutch, French and English navies. It is still actively garrisoned, but is open to visitors and is a great place to explore, especially for history buffs. There is a nice Hindu temple atop the cliff at the end of the peninsula with spectacular views. There are also kiosks where you can relax with a cold coconut. Friendly spotted deer roam the fort's forested areas, apparently descendents of a pair kept as pets by an English family in the 1800s.
The final resting place of over 600 Allied soldiers and sailors who died in Trincomalee during World War II. You will be asked for a donation upon entering. The best time to visit is at sunset when the light shines directly on the gravestones.
temple
This is a beautiful Hindu kovil that provides a good view of Trincomalee town, and of the fishing boats in front of it. It is an important temple to the local Hindus, who regularly visit it for prayers and festivals. During festivals, it is common to see drummers, dancers, men with pierced tongues and women holding pots of milk.
Uppuveli beach is about 3 km north of town. Restaurants and hotels are mostly gathered around Sarvodaya Rd. There is litter on the beach but the area around Fernando's bar is usually the cleanest.
15 km south of Trincomalee. It is part of a Navy base so there is a small entry fee. The beach is divided into public and private areas. The public side is free but lacks facilities. The private side has chaises longues and shade but you need to buy something. A very beautiful beach and a hidden gem.
The sleepy village of Nilaveli is 16 km north of Trincomalee. Because of the beach there are many hotels there. This is also the jumping-off point for day-trips to Pigeon Island.