Road names aren't posted in Antigua, so study a map before you start exploring. Locals generally give directions in terms of landmarks that may not seem much like landmarks to you (turn left at the yellow house, right at the big tree). It's a good idea to wear a swimsuit under your clothes while you're sightseeing -- one of the sights to strike your fancy may be a secluded beach.
St. Johns, Antigua's capital and home to about 40,000 people (approximately half the island's population), lies at the inland end of a sheltered northwestern bay. Although it has seen better days, a couple of notable historic sights, such as the cathedral and a museum, housed in an old building, make it worth a visit, as do some good restaurants and waterfront shopping areas. Besides the Redcliffe Quay and Heritage Quay complexes, there's also the public marketplace, at the south end of town.