Royal Naval Dockyard in Sandys Parish (accessible by fast ferry from Hamilton in 20 minutes) is Bermuda's biggest half-day excursion — the National Museum of Bermuda occupies the old commissioner's house and ramparts, with extensive maritime and military collections, and Dolphin Quest is located in the Keep Pond.
Crystal Caves in Hamilton Parish (bus accessible) are a genuine natural wonder: limestone caverns with pontoon bridges over deep clear cave lakes, formed over millions of years. The adjacent Fantasy Cave is equally impressive.
St George's in the east is Bermuda's first capital (1612) and a UNESCO World Heritage Site: narrow lanes, 17th-century buildings, and the Unfinished Church. Accessible by bus in 40 minutes.
Scuba diving and snorkelling: Bermuda has some of the Atlantic's best wreck diving, with over 300 wrecks in the surrounding waters. Dive operators in Hamilton and at Dockyard run daily trips.