Mammoth Cave

When you play this land exile the target creature.
If you do, tap the Mammoth cave.
This land doesn't untap during its controller's
untap step as long as target creature is in exile.
{ut}: Return the exiled creature to the battlefield
under its owner's control.
{t}:Add {b}
I was lost, completely, hopelessly lost in the vast and labyrinthine recesses of the Mammoth Cave.
The Beast in the Cave—H. P. Lovecraft