exploring the islands on foot
St Mary's - from Hugh Town the outcrop of land to the west contains an eight-pointed star castle known as the Garrison, while the main bulk of the island to the east contains a coastal path.
St Agnes - a very hospitable island, stepping ashore you are faced with the island's only pub, the Turk's Head. The two main features to see are the lighthouse, built in 1680, and the connected island of Gugh which is accessible across a sandbar at low tide. The sandbar provides a lovely clean beach.
Bryher - walk across the island to Hell Bay to see the Atlantic waves crashing in and for a hot chocolate at the Hell Bay Hotel, then back along the eastern shore where you can see Hangman Island, allegedly a gallows site in the English civil war.
Tresco - walk a circuit round the southern part of the island culminating at the Abbey Gardens.
on the water
Boat trips: large number of boat trips are available from wildlife watching to island circular tours. On St. Mary's look out for the notice boards of the boatmen's association (http://www.scillyboating.co.uk) at the quay. On the off-islands check with the island boat companies.
World Pilot Gig Championships (http://www.worldgigs.co.uk/) are held every year in May. Over 100 crews of traditional Cornish wooden rowing boats compete. The last night party is legendary.
birdwatching
Keen birders will need no introduction to the Isles of Scilly. This is the Mecca of birding in Great Britain and probably the whole of Europe. The islands are ideally positioned to be the point of landfall for many scarce migrant species in spring and especially in autumn. Each October, many hundreds of expert birders from Britain and further afield converge on the islands.
The slightly less keen will still find plenty to interest them in the summer months as the islands host several important seabird colonies.