The Knights of the Round is a very large area, this is the start of it.

Make sure you kneel to the guards at the gate, or the next room north will have no floor and have an instadeath room below it. If you kneel, the room has a floor and the gate is unlocked.

Walk ( 4s, w, 2n, give 5k coins receptionist, unlock/open n, 2n, e, ne, nw, 2ne, enter ) to get from DH to the room marked in blue.