The 17th century cathedral on Ludgate Hill in the City of London is one of the capital's most iconic buildings. Designed by the illustrious Sir Christopher Wren, St Paul's was the tallest building in London until as late as 1962. Use the touch-screen multimedia guides or take a guided tour to learn about the famous interior or, if you're feeling fit, climb up to the Whispering Gallery and try out the acoustics. From there you can carry on making your way up to the Golden Gallery atop the dome, where you'll be rewarded with breathtaking views of London. You can also descend into the crypt where you'll find memorials of important historical figures such as Admiral Lord Nelson.