Head to cosmopolitan St Thomas, the second-largest of this chain of islands. Like St Croix, it has many associations with the Danes and retains much Danish influence. The main town, Charlotte Amalie, is the group's capital. Imported goods from all over the world make it a marvellous shopping centre and stores tucked into remodelled Danish warehouses line each side of the picturesque Main Street. Cobblestoned alleys with numerous boutiques lead down to the waterfront. Blackbeard's Castle is the earliest fortification in the US Virgin Islands. Other attractions include Fort Christian, built in 1672; the Coral World Observatory; the Frederick Lutheran Church of 1850; Government House on Government Hill (1866); Venus Pillar on Magnolia Hill; Bluebeard's Tower, the 19th-century pirate's one-time abode; and the Synagogue on Crystal Gade, one of the oldest in the western hemisphere. On the northern coast is Magens Bay, claimed to be one of the world's top 10 beaches.