The only safehouse that lets you break reality itself

The Prickle Pine Safehouse is the only safehouse that grants access to the Hidden Interiors Universe — a massive out-of-bounds void above the map. By using the kangaroo cheat for super-jump, you can phase through a specific wall with missing collision, then parachute down through empty sky to reach a glitched Ghost Town that exists miles below. The jetpack doesn't work here because the interior is placed beyond the game's ceiling height limit.

Source: Prickle Pine Safehouse — CC BY-SA