When Treva's Ruins enters the battlefield, sacrifice it unless you return a non-Lair land you control to its owner's hand.
{T}: Add {G}, {W}, or {U}.
This land is of type “Lair” only; other subtypes have been removed. It is not a basic land.
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.