Olympus gateway

The Olympus Gateway is a permanent gateway between the plane of Heaven and the mortal plane. Being built by the olympians after the Great Division of the planes, it allowed them the ability to travel to and from the mortal plane without any energy cost granting them almost exclusive access to heaven fire they could extract from the mortal plane.

Destruction
The gateway was ultimately destroyed as all mortal beings (primarily humans and demi-humans with the help of a few remaining primordial gods) united in revolt against the Olympians who they felt were taking advantage of mortals without offering anything in return. This battle became known as the assault on Olympus.