Echoing Deeps is a rare Land — Cave card from The Lost Caverns of Ixalan (LCI), collector number 346. Current market price: $0.50 (foil $0.77), TCGplayer market prices via Scryfall.
You may have this land enter tapped as a copy of any land card in a graveyard, except it's a Cave in addition to its other types. {T}: Add {C}.