Tamara and I were in London yesterday. We happened to see this small building, which is the entrance to the Greenwich Foot Tunnel.
The tunnel goes under the Thames, 15 metres below the river. It runs from Greenwich on the south side to Tower Hamlets on the north side and was opened in 1902 with lifts installed in two years later.
New lifts were installed when the tunnel was renovated in 2012. There’s a plaque that you can see lower left of the photo, the details the history of the tunnel.