Langley, Richard II : 3, 4

This is likely to be at Kings Langley in Hertfordshire. Edmund de Langley, the Duke of York, was born in and owned a palace here that has since burned down.

I'm not sure how to mark the place but I can pinpoint it for you. A school is on the site of the palace and the postcode is WD4 9HG.

Richard II was buried here (before being moved to Westminster)

I assume that this is also the site of:
The Duke of York 's Palace, Richard II : 5, 2 and may be "a royal palace" mentioned in other scenes.