Where is the bomb

Hint 1 of 7:

You've gone up the ladder from the sewer ?

Hint 2 of 7:

You've found a non-obvious doorway to go through ?

Hint 3 of 7:

Well, it's not like it's so big an elephant couldn't hide it!

Hint 4 of 7:

MOVE ELEPHANT.   +1

Hint 5 of 7:

Things are not as they seem.... just like in the torture room.