Site: Golden Jubilee sundial (1 memorial)
SW1, St Margaret Street, Old Palace Yard
This sundial was commissioned by Parliament and installed as part of the overhaul of Old Palace Yard. The yard was paved in granite and its outline defined by gas lanterns. The Google satellite view shows how Whitehall cuts diagonally across the yard which is part of the Palace of Westminster.
Old Palace Yard was once the go-to place for executions: Sir Walter Raleigh, Guy Fawkes and 3 of his fellow-conspirators, and James Hamilton (1606 -1649). But we have found no commemorative plaque.