Obelisk is an unsplicable non-solid block which was added alongside the addition of Desert Blast. Obelisks can spawn in Desert-blasted worlds.
If a Sungate is present in the world, 7 Obelisks can be activated by players by punching them. The gate would function as a portal as long as the Obelisks are still activated. An Obelisk will return to its deactivated state within 15 seconds.