Ah, the BT Tower. It’s only 189 metres, so it’s not even in the top five anymore. But it was the tallest when it opened in 1965. And it has a rotating restaurant at the top that now just spins empty, like a sad, abandoned lazy Susan. The public can’t visit, unless you win a lottery or have a secret spy meeting.
Also, fun fact: The BT Tower is technically not a building; it’s a telecommunications tower. So if you’re a pedantic nerd, The Shard still wins. Chew on that.