From what I can see, if you want to avoid the sliding floor completely, you need to approach this place from the stairs on the western side, and go south along the western edge. After an encounter with with monsters, you find yourself in a room with four exits in addition to the one to entered by, two leading east, and two leading south. Facing south, take the left of the two southern exits, and follow the path to the room with the sliding floor. Stand on the square just outside the room, open the door, and cast Jump.

Then go:
2 squares north
1 square east
2 squares north
1 square west
1 square north
1 square west
2 squares north
1 square east

and go through the door to the north.

After going along a short passage, you will go north through another door and, after a battle with a grey minotaur and a number of ordinary ones, you will find two treasure chests.

Incidentally, you don't need to go there if all you want is the gold key. It's nearby, but you need to do a spot of Searching to find it **Hint**!

Oh, and one other thing — don't desecrate that statue. You might just get more of a fight than you're prepared for just at present!