Treva's Ruins
Planeshift — uncommon
Land — Lair
Treva's Ruins rulings:
2005-08-01: This land is of type “Lair” only; other subtypes have been removed. It is not a basic land.
2004-10-04: If you don't want to unsummon a land, you can play this card then tap it for mana before the enters the battlefield ability resolves. You may then choose to sacrifice it instead of unsummoning a land.