This 114.5m-tall (376ft.) vertical scribble, a publicity exercise by a steel concern that is now failing, has observation decks at 76m (249 ft.) and 80m (262 ft.), but it barely matters when there’s not much to look at. It originally overlooked the Olympics, but with the torch and the games gone, it now peers into a stadium many miles from town. So tragic have attendance numbers been than in 2016 it desperately added a 40-second tube slide, the world’s longest and tallest—narrow enough to bonk your head and fast enough to smash your phone—that drops from one of the observation levels, wrapping around the structure 12 times. They put a helmet and elbow pads on you, tuck your feet into a cubby at the end of a mat, and send you screaming. It also offers an abseil thrill from 80m/262 feet high (; [tel] 020/3198-0407; £85; minimum age 14, maximum weight 120kg/264 lb.). Wear a jacket because it gets windy in the exposed areas. And no, it doesn’t orbit.