As well as its distinctive shape, it really is a very large building (37 floors plus the Sky Garden at the top). The rooftop I took this photo from is on the 15th floor!
@nigelrogers I do recommend a visit, especially to the Sky Garden, the vast space at the top. I think it’s free to visit but you do need to book a slot. Alternatively you can make a reservation in the restaurant at the top which has stunning views across London
