The house that Dmytro Perov's family built in the late 1800s was seized by the Bolsheviks and is now an abandoned building. Perov was unaware that the owners of the site wanted to build on it and that their office was located at a house with no roof and collapsed walls.

The land around the former family home was rumored to be home to ancient caves. He said it was a family legend. The Pecherska Lavra, or Cave Monastery in English, is one of the most famous cave complexes in the world.

Perov wanted to find out if his grandmother's story was true. He and his friends went to the site to look at the ruins of his grandmother's house. There is a pile of bricks on the hillside. There is a tunnel that goes into the hill. They used their phones as torches to climb in.

The entrances to four tunnels have been found behind the house. The lower tunnel is twice as long as the upper one. The rooms and cubbies inside the tunnels are thought to have been used to place lanterns.

Timur Bobrovskyy, head of archaeology at the StSofia state museum in Kyiv, has hailed it a significant and special discovery and concluded that it must be preserved. The caves are more than a thousand years old and have similarities to Medieval monastery cave complexes. The caves have had visitors before Perov, but he thinks they didn't realize their importance.

The Algiz, or Chicken's foot, is a runic symbol used by the Varangians, the Swedish Vikings who settled in Kyiv.

The developers and their allies in the city council are still pushing for planning permission despite the find. The documents needed to classify the area as protected are being gathered by Perov and other people.

Efforts like this are not always succesful. Perov's fight is part of a larger effort by civil society actors against the rampant corruption among the country's elites. Bobrovskyy said it was a second front.

An online petition has been started to repeal a new urban planning law adopted by the Ukrainian parliament.

Cave

Experts say the cave complex should be preserved for its ‘indisputable and cultural value’. Photograph: Isobel Koshiw/The Guardian

It is believed that it will reduce corruption by digitalising a lot of the process. Critics say it gives power to a single ministry.

The new law would not allow the deputy to stop the destruction of the city's cultural heritage according to her. She said that developers don't know how to make a restored building worth money.

Perov emerged from the other end of one of the tunnels to see a tall apartment building next to him. Construction work on the apartment block was stopped in 2008 after a set of caves was found. The construction workers told the state archaeologists that the caves had collapsed. Perov wants the site to be turned into a museum, which would include his former family home. If my great-grandfather was alive today, he'd know more. Perov was certain that he found them.