As per the census of 2010, the population of the district was 22,114 out of which 10,679 lived in the town of Derinkuyu.
The district covers an area of 445 km2 and the average elevation of the district is 1,300 metres, the highest point being Mt. Ertas at 1,988 metres.
The historical region of Cappadocia where Derinkuyu is placed, comprises of various historical underground cities which have been carved out of a unique geological formation that were not generally occupied and is now a major tourist attraction.
It extends to a depth of approximately 60 metres and was huge enough to shelter around 20,000 people with their food stores and livestock and is also one of the largest excavated ground city in Turkey.
More than 200 underground cities of at least two levels deep have been discovered in the areas between Kayseri and Nevsehir with 40 of which have been of at least three levels and the troglodyte cites at Derinkuyu and Kaymakli are the two best examples of the underground cities.
Carved out of Unique Geological Formation
There are around 600 outside doors to the city which are hidden in the courtyards of surface dwellings and the underground city is 85 meters deep containing the usual rooms which is normally found in an underground city, with cellars, storage rooms, refectories, churches, stables and lot more.
From the third and the fourth floors onwards the descent of vertical staircases lead to cruciform plan church to the lowest floor.
A ventilation shaft of 55 meters deep was also used in these underground dwellings and at least 15,000 ventilation ducts to provide fresh air deep within the underground cities were discovered.
Most of the floors were not provided with water wells up to the surface in order to guard them from being poisoned at the time of raids.
Protection for Attacks
These underground dwellings were complete with chimneys for air circulation, niches for oil lamps, wells, water tanks, as well as areas to place the dead temporarily till a suitable place for burial was found.
They also had carefully balanced moving stone doors; resembling mill stones that were constructed to quickly block the corridors in case of any incidents of attacks which only operated from one side.
From observation, it is unlikely that these underground cities could have been intended for permanent dwelling or long stays but built to safeguard from attacks which could accommodate large numbers of people with their livestock for a long period of time.