When you get off the boat at Greenwich, you'll find the Cutty Sark immediately in front of you. This handsome vessel is a tea clipper and one of the most famous ships in the world. She was built to bring tea quickly from China.
The odd name comes from a short story by Robert Burns. It tells of a farmer named Tam O'Shanter who saw a beautiful witch dancing in a short petticoat, which was called a 'cutty sark' in ancient regional Scottish. Overcome by the dance, he called out "Weel done 'cutty sark'!" and was then chased by the witch, who was furious to have been spied. She was hot on his heels until he crossed the River Doon and was saved -- witches cannot cross running water.
The Cutty Sark reopened on 26 April 2012 after a six year conversation project that cost £50 million. You can now explore below the ship in a new glass-roofed visitor center and even have a cup of Twinings Cutty Sark-inspired tea in the cafe. Visitors can also go to the hold and learn about the other cargoes she carried (it wasn't all tea), discover how the sailors lived and worked as well as go on the main deck and pretend to steer - it's a great photo opportunity!
From here you can see the entrance to the Greenwich Foot Tunnel but I'd recommend going in Discover Greenwich which includes the Tourist Information Centre and an exhibition about Greenwich, and is part of the Old Royal Navy College.