Hidden Cataract is a common Land — Cave card from Modern Horizons 3 Commander (M3C), collector number 348. Current market price: $0.23, 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.)