Card Name: Cavern of Souls 

Types: Land 

Card Text: As Cavern of Souls enters the battlefield, choose a creature type. : Add to your mana pool. : Add one mana of any color to your mana pool. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Expansion:  Avacyn Restored

Rarity: Rare 

Card Number: 226 

Artist: Cliff Childs