Head down the stairs until you’re back in front of the monastery’s facade. Facing it, cross the arch on the far right of the facade. Make sure that you have a ticket! To gain access to Virgin's niche, it’s highly likely you’ll need to queue for a bit. Walk straight ahead, and follow the path. When you reach the steps under the alabaster portal, make your way up. Continue walking and pass through the two silver doors. You’ll find the Virgin's chamber in the next room.