This fan build is from Gieljan de Vries (Oorlof on discord & forums), titled "Four Sewers Deep".
This build was for the annual 12x12 Build of Forgemas challenge on the Discord, and takes the sewers to new heights!
Here is what he says about the build:
"I was inspired by the idea of an ordinary house on top of a vast network of sewer-dungeons.
Sewers is a set I don't use nearly as often as I should, and I loved the challenge of going as vertical as I could with them. No magnets to hold them together, so that took some balancing! To make it into the 12x12 challenge on Discord, I also wanted to fit this build on one terrain tray. I was pretty sure it would be impossible to go four levels up, but the idea of these vast depths was just irresistable. It turns out that two Ancient Pillars on top of each other are plenty stable, and if you turn a city stone floor-and-corners upside down, it makes a fun cellar!
From the cellar, you could go explore the burrows behind the collapsed wall...but that's another build entirely. Follow the sewers through the inevitable ratmen, green slime and what have you, and they snake down, down, ever down through increasingly older and more worrying architecture. Eventually you arrive in this enormous cistern held up by monstrous stoneworks. Something splashes in the muck, four eyes and countless teeth glinting. There's a dark shrine here, pillars covered with snakes and greenish light glowing beyond iron bars. Surely this place needs a couple of adventurers to clear it out..."
For this build they used:
"I didn't aim for a minimalist build, so there's little touches in here from a lot of different sets.
The main sets are:
Terrain Tray - cave water / running water (as a base)
Monster sewer set
Ancient Pillars x2
Stone city starter set
Slate (stone) Roof Add-on Pack
Terrain Trays Four-Pack Multi-Size: Rough Stone/Water (to hold the house)
...and then there are finishing touches from Encounter 06 Acid Bath, Vaulted Doors, Walls & Pillars, Double Doors, Ledges, Diagonal Walls and Burrows Accessories. Surprisingly, no Mountain Cliff Pack, which is an absolute workhorse for almost all of my builds!"