The Underground Railway Museum, also known as the Millennium Underground Museum, is a museum located under Deák Ferenc square in the centre of the Hungarian capital city of Budapest. It is accessible from the pedestrian subway system that links the square to Deák Ferenc tér metro station and is housed in a tunnel that once carried the tracks of line M1 of the Budapest Metro.

Deák Ferenc tér is a transfer station on the M1, M2, and M3 lines of the Budapest Metro. It is located under Deák Ferenc square in central Budapest, the capital city of Hungary. Owing to its direct transfer connection between three out of the four metro lines Budapest has and its downtown location, it is one of the busiest stations in the system.