St. Thomas, the most populated of the USVI, lies a little more than 10 kilometers (6.5 miles) across the water from St. John. Here you'll find Charlotte Amalie, capital of the U.S. Virgin Islands and one of the Caribbean's most popular cruise ports. For passengers keen on convenient shopping, Havensight Mall sits right on the cruise dock. The downtown historic district offers cobblestoned lanes and colonial-era buildings, including Fort Christian, a National Historic Landmark built by Danish and Norwegian colonists in 1680. Take a walk up 99 steps to reach Blackbeard's Castle, actually a Danish watchtower, for great views of the harbor.