Domed glass roof of the Greenwich Foot Tunnel entrance

This is the southern entrance to the Greenwich Foot Tunnel, which takes pedestrians underneath the Thames to the Isle of Dogs. I took this photo in March this year - we were visiting Greenwich during our London trip and had gone to find the Cutty Sark. Visually, though, I found this nearby building much more interesting (I think I was probably the only one photographing it, rather than the ship!). This entrance building houses the lift and spiral staircase down to the tunnel, which I really want to walk through one day.

Camera/lens settings: ISO 100, f/10, 1/125s, 18mm, hand held.