This small stone stairway which now sits in the midst of a grassy expanse at the back of the Ministry of Defence was once part of the Palace of Whitehall.
Named for Queen Mary II, wife of King William III, for whom they were designed, the stairs were part of a terrace built in 1691 abutting the Thames in front of an old river wall constructed for King Henry VIII.
Designed by Sir Christopher Wren, the stairs were one of a pair located at either end of the terrace which gave direct access to the river – and state barges – from the Royal Apartments.
Excavations in 1939 during construction of the MoD revealed the Tudor river wall, the terrace and the northern-most of the two flights of steps. The upper part of the steps have been repaired and the terrace and wall reconstructed.
The steps and palace fragments are now a Grade I listed monument.