Menagerie
The Menagerie is accessible from Floors 3-5. It leads to the [Ice House].
Since the staircase to the Ice House is surrounded by a gate that only opens from the inside, it's not immediately obvious how to enter. You can either BOMB the walls/gates surrounding the staircase of simply fall into a pit in the Menagerie's ice display. Falling through a pit is slightly dangerous: you can take a little bit of damage and also end up in a random location of the Ice House. Be ready for a fight.
The menagerie contains exotic beasts like tigers, monkeys, elephants, and others.