Hideaway

"You speak of the city on the back of a beast. It is difficult to find, for it roams of Unterzee - above and below. It scorched its belly on Mount Palmerston and snapped the top of Massey's Shaft. It blocked the harbor of Adam's Way and gave birth to the Grand Geode. Why, last you heard, it was making to London..."

That's a giant crab alright. (art from Sunless Sea)

Drilled and tethered to the back of a giant arthropod lies Hideaway, a city of outcasts and fugitives from all walks of life. From the streets of London to the water paths of Khan's Heart, they find their furtive way here; given these people come from all over, it's only fair that the city is quite a cultural melting pot, always alive with festivals and rituals. Visitors, too, can take part in these festivals and, if one is willing and brave enough, one can hear these rejects' tales straight from their mouths.

Hideaway holds a dark secret that its higher-ups will kill to protect. The beast, despite its great size, is still growing. And, if arthropods down below behave like they do on the Surface, this means that the beast upon which the city is built is going to molt...