It's a ferris wheel. Yeah, it's a really big one, but still. You can ride on one of those at any county fair in the world, and they don't cost 21 pounds sterling and take away valuable time that you could spend actually exploring London. The views are nice, but not worth the expense, and the ride only lasts thirty minutes until you're unceremoniously booted back to the ground. If you want to stick to that area of the city, take a few obligatory pictures of yourself in front of the Houses of Parliament and the Elizabeth Tower, then explore the surrounding areas. You could walk along the South Bank, the underrated and less crowded side of London, and end up at Shakespeare's Globe. There, you can either take a tour of the theater (painstakingly reconstructed in the mid 1990s), and if you're really committed to the Bard, stick around for a show. Not everyone likes reading Shakespeare, but everyone likes Shakespeare performed at the Globe - there's something about it that's magical. For a fraction of the price of a thirty minute ferris wheel ride, you can have an authentic experience as a Groundling in the front row.