Sunken Citadel
The Lost Caverns of Ixalan — rare
Land — Cave
Sunken Citadel rulings:
2023-11-10: "Land sources" include any objects with the card type land. This means you could spend the mana to activate an ability of a land you control or a land card in your hand or graveyard, for example.
2023-11-10: You may spend the two mana added by the last ability on the same ability or on two different abilities.