Considered little-known and hard to find, the cave was located in a deep, narrow valley in the mountains, only accessible through a maze of passes and other valleys. Its tunnels extended far into the depths, and included a number of caverns, sinks, and pits.
The valley itself was a small sub-tropical forest, full of oak, pine, and bamboo trees, surrounded by the jagged icy rock of the high mountains.
The actual home of Monkey was a series of large caves, each furnished with some of the most expensive furniture, rugs, paintings, and treasure, much of it stolen from around the world.
The cave system was actually located in its own demiplane, located between Toril and the Celestial Bureaucracy. Its purpose was to allow Monkey to easily travel between planes via gateways located in the caves.
While the cave was seemingly unguarded, Monkey had actually trapped the gates leading to it. One could enter the caves from Toril freely, but one couldn't leave without knowing a password. The gates leading from the cave to other planes worked the exact opposite way, one could freely leave into the other planes from the cave, but one could only enter the cave from the other planes by knowing the password.
While being the home of Monkey himself, the cave and surrounding valley were also home to a number of wild animals such as boar, bears, leopards, and monkeys.