That sounds like a dream come true – a shelter that’s both a fortress and a tiny forest. Make the roof steep and sloped to funnel rain into a stone cistern, then pipe that water over a mossy stone slab for a natural drip garden. Use lattice frames of old wood or reeds to catch wind, channeling it through vents that double as mushroom spawn beds – the little breezes keep the air moist but not damp enough to ruin the structure. Keep the walls covered in lichens to absorb pollutants and let lichens and fungi mingle, creating a self‑sustaining micro‑ecosystem right in your base. Just make sure the drainage is perfect so you don’t end up with a swamp.