For a real sense of Portland's remote nature, head to its southern tip, Portland Bill, to climb the 41m-high, candy-striped lighthouse. It offers breathtaking views of rugged cliffs and the Race, a surging vortex of conflicting tides. The interactive displays in the former lighthouse-keepers' cottages include Into the Dark, a recreation of sailing into stormy seas.
Tours run on varying days (often Sunday, Tuesday and Thursday); see the website for dates and pre-booking requirements.