Go through the Beit-Quad archway and walk straight ahead towards the union, but don't go inside.
After you pass the union's picnic tables and just before the door to the union, turn left.
Go down the metal stairs next to the fire escape and head into the door immediately in front of you.
Once inside, turn immediate left + go up the couple of concrete steps to the door. If it's closed try swiping your college ID on the reader or knock on the door.
Walk along the beautifully decorated corridor.
The second door on the right is caving stores!