Calamitous Cave-In is a uncommon Sorcery card from The Lost Caverns of Ixalan (LCI), collector number 139. Current market price: $0.10 (foil $0.13), TCGplayer market prices via Scryfall.
Calamitous Cave-In deals X damage to each creature and each planeswalker, where X is the number of Caves you control plus the number of Cave cards in your graveyard.