Hidden Cataract is a common Land — Cave card from The Lost Caverns of Ixalan (LCI), collector number 273. Current market price: $0.19 (foil $0.25), TCGplayer market prices via Scryfall.
This land enters tapped. {T}: Add {U}. {4}{U}, {T}, Sacrifice this land: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)