The Undara Volcanic National Park preserves the lava tubes and surrounding area in the west of the Atherton Tablelands. The lava tubes are amongst the largest and longest on the planet. They originate from an ancient shield volcano when torrents of lava confined to a valley crusted over and formed a roof. Summer rains stream into the caves and pool there. Bayliss Cave is known for its extremely high biodiversity. The national park was declared in 1993 and covers 615 km².