The second underground city in Saratlı Village, St. Mercirius Underground City and Church have peculiar features.
While the site was frequently used around 250. A.D. when Christianity was forbidden, its use in that period was mostly for shelter. St. Mercurius was a military officer who lived between 225 – 250 A.D. He was born in Cappadocia during the Roman period and was exiled to Cappadocia after his declaration of his Christian faith. He was decapitated in the region and his corpse was sent to Egypt.
There are seven floors in the underground city, three of them have been cleared for touristic visits. The entrance is through a Seljuk period inn known as Develik among the local people. Access to other floors is through corridors and chambers, while all passageways lead to the church. Altough the churches in underground cities are usually small, the church here is about the size of a cathedral. In the church, there is a seperate chamber accommodation the graves of some children and adults.
The church was used as a church until late periods. There are graves in the church. During the excavations in the church, about 20 graves belonging to children and adults were unearthed and most of them still had bones inside. In one of the graves, the skeletons of a male and a female were found on top of each other. There are various engravins of the cross in the church. The site was used mainly used mainly during the Eastern Roman period.
Storage jars were also found in the city. In one corner of the city, there is a tomb known as Develi Chamber where local people do offerings. In the chamber next to this one, there can be seen embossed images of ducks or swans carved into the stone wall.