Tall Mansion at the Pale Forest

At -520 ~ 280 there's a woodland mansion in a pale forest that generated on the edge of a cliff with its foundation stretching deep underground into a massive cave system below. The result is a towering structure that looks more like a fortress than a mansion, with stone pillars dropping dozens of blocks into the darkness beneath it.

A pillager outpost and a village with a blacksmith are both nearby, so you can gear up from the village before taking on either the mansion or the outpost. The cave under the mansion is worth exploring on its own, and having direct access to it from inside the mansion's foundation makes for an unusual base setup if you decide to build around it.