Riddle

51.512288, -0.115721 (OpenStreetMap, Google Maps, Yandex Maps)

These places starting with M are not 16 700 km apart but merely 150 metres. Entrance to the underground station across the road south of the eastern of the two. Padlock locking the grid
The number above the keyhole

Detailed answer

These are Montreal Place and Melbourne Place. Across the road there is a closed Strand station entrance.

Answer: 440


440

Present in routes of categories Sphinx

Passed by: 10/22 (45%).

By categories:

  • Sphinx: 10/22 (45%)