A Crimson Gateway is a natural structure which can warp objects between locations and worlds. The portal can be activated using redstone signals. Smaller redstone signals can produce items or rarely mobs. I haven't tested higher signals, but I hypothesize that it would result in the transport of full structures.

Trying to damage a Gateway will harm the attacker, and succesfully breaking one will result in the world surrounding it to collapse. Inside of the Gateway is the Crimson Void, an endless space connecting different places and worlds. Crimson Shards are created upon the destruction of a Gateway. When enough shards are brought together a exit to the void will be forcibly opened.

They can be opened to specific points using precise signals, however I've struggled to pull it off consistantly.

There are four know 'legitimate' Crimson Gateways. One at the IKB Mesa, one in the desert, one mega gateway in the snowy mountains, and one near the Eiffel Tower