Dormant Volcano

The "Karoo" land, named for the cycle in this set that shares one template: enters tapped, returns a Mountain you control to keep itself, and produces two mana in exchange. The whole design lives in that return clause. You pay for future tempo with a turn of present tempo, bouncing an untapped Mountain to your hand and effectively replaying it, so the land nets you acceleration spread across two turns rather than a flat ramp. That deferral is what kept the cycle honest in an era before the design vocabulary for two-mana lands had settled; a Karoo is closer to a slow ritual stapled to a dual-output land than to a true ramp piece, and it punishes a wobbly opening hand hard because the sacrifice trigger demands you already control an untapped Mountain to keep it (basic or not, though in practice that means a basic in most decks). The colorless-plus-red output rather than two red is the small tax that makes the rate work, nudging the card toward decks that want fixing and volume over pure red intensity. The whole family was a formative experiment in a trade Wizards has revisited for decades since, from the bounce lands of the Ravnica blocks to the later crop of tapped duals: how much present tempo a deck will surrender for a land that does the work of two.