How to Build and Light an Undergarden Portal

Gather the Frame Materials

You need a Catalyst to open the portal. Catalysts generate naturally in the Undergarden, so your first trip requires another route in. Once you have one Catalyst, place it as the centerpiece of a frame built from Depthrock or Dreadrock blocks. A rectangular frame of these stones surrounding the Catalyst is the standard layout.

Activate the Portal

With the frame complete and the Catalyst set in place, the portal lights and you can step through into the Undergarden. Keep a spare Catalyst in reserve: a Crumbling Catalyst is a degraded variant, so if your frame ever fails to light, swap in a fresh Catalyst rather than rebuilding the whole structure.

Return Trips

Portals are your only reliable way back to the surface, so mark the overworld side with something visible. Bring Cloggrum Lanterns to light the area around the frame — the Undergarden is dark and hostile, and a lit arrival point keeps you from walking into a Boomgourd or a drop the moment you return. If you plan to haul ore home, place a chest beside the frame and stock it with Cloggrum Buckets and spare tools before you leave.