(Slagheap Caves isn't a spell.)
Slagheap Caves enters the battlefield tapped.
: Target player exiles a card from his or her graveyard.
: Add to your mana pool. If you played a land this turn, Add to your mana pool instead.
: Target player exiles a card from his or her graveyard.: Add 
to your mana pool. If you played a land this turn, Add 
to your mana pool instead.
