Royal House, Machynlleth. This is a copy of a postcard of Royal House, a medieval building situated in Penrallt street, Machynlleth. It is said that David Gam was imprisoned here in 1404-12, for attempting to assassinate Owain Glyndwr. Charles I is supposed to have slept here on his way to Chester. This photograph shows the lower end of Royal House and the prison of David Gam. On the left of the picture is the old town hall.