An equatorial sundial, the gnomon (= the point) points North, its angle with horizontal is 51° 30' 22.07". This is the latitude of the sundial's position.
Taken at 16:14:41 GMT but the time on the clock is 1 hr out because of BST.
The focal plane has been tilted so that it passes over the surface of the sundial.
There is another one in Berlin, Germany.