Chained to the Rocks says:
Enchant Mountain you control. When Chained to the Rocks enters the battlefield, exile target creature an opponent controls until Chained to the Rocks leaves the battlefield. (That creature returns under its owner's control.)
Does mountain in this instance mean a card that is named "Mountain" or a card with a mountain sub-type? For example Sacred Foundry has the sub-type "Mountain Plains". Could I enchant this land with Chained to the Rocks?