Beneath the Abandoned Cottage was a young Beholder’s secret laboratory, inside which he was trying to raise an army of warforged to take over part of the continent. Luckily the player’s stumbled onto him before things really got going and they only had a few warforged and mind controlled hobgoblins to deal with.
Also luckily, the players found the real secret door in the cottage, instead of the fake secret door (the fountain) that actually into that pit of acid west of the stairs.
The party had fun knocking creatures into pits of lava, and built a few warforged of their own to guard the cottage before moving on.
As this was the first actual dungeon I’ve built, I’m still working on the style. I think it looks good, but it really needs some better lighting and shadows.