Mentioned by Santorini Dave
London with Kids - The Best TOURS & THINGS TO DO
"London’s tallest skyscraper with superb city views from the Skydeck on the 72nd floor. The 306m-tall building is the tallest in the EU and on a clear day you get 360-degree views for up to 40 miles. Using binoculars you can zoom in on London’s different landmarks, from the Houses of Parliament to Tower Bridge."