Pogonia

Pogonia is one of the largest settlements on Nea. 
It's a underground structure stretching for 3 km on both sides of a canyon. On the surface only the ventilation towers and some landing openings for pterocopters are visible but below the surface a giant networks of tunnels and halls run through the rock. The canyon is the heart of the city. It contains a small river which is the main source of water for the extensive gardens on the canyon walls. These gardens are not only full of wonderful flowers but also many heat resistent crops which help to keep Pogonia mostly self-sufficient. The people of the city get their water mostly through fog catchers which collect the moisture of the air, especially in the morning. 
The ventilation system of the city is inspired by ants, organic waste is stored in deep caverns where is becomes fertile soil for mushrooms. The heat of the decomposing waste rises and leave the city through the ventilation towers, this creates a under-pressure which draws fresh air through tunnels which lead to the surface and especially into the canyon.
Beside the fog catchers the people of Pogonia also use fossil ground water which was stored deep within the rock for millions of years.

Nea: hyrotrioskjan.deviantart.com/a…