A former hotel, abandoned in the mountains and kept off limits by a group of mysterious guards. A former foreign minister stumbling upon the road that leads to it, and gets arrested. Rumours of something sinister hidden deep beneath it.

No, this is not the elevator pitch for a TV series based on the mysterious deaths of six people connected to a hut in Petrohan. This is the story of Object 17, which the hacks sometimes dub "Bulgaria's Area 51."

In the 1970s, the story goes, the Bulgarian army constructed a huge hotel in a secluded spot near the village of Lesidren, a few kilometres south of the main Sofia-Varna road. The hotel was not a hotel at all. Its ambitious Brutalist architecture was a decoy for a multi storey underground bunker to be used by the Warsaw Pact command in case of war.

Everyone involved in the construction of the facility was sworn to secrecy and they have kept the secret as time passed. Communist Bulgaria collapsed, the Warsaw Pact dissolved and the abandoned hotel started crumbling under the elements. Something very important is presumably still hidden there. It could be nuclear missiles, which Communist Bulgaria was not supposed to host, or important government documents, or psychotropic weapons – or something else entirely.

Whatever it is, anyone approaching Object 17 would be greeted by some very serious men who would politely ask him to get the fcuk out of there. One of these people was Solomon Passy, Bulgarian Foreign Minister in 2001-2005, the man who promoted Bulgaria's accession to NATO in the 1990s and oversaw its joining in 2004. He was on a quiet walk with his family sometime in the 2000s when he stumbled upon the abandoned hotel. As the guards materialised, Passy's 10 year old son became so disquieted that he reportedly asked: "Are they going to shoot us now?" The men did not shoot. They escorted the day trippers away and told them never to come back. Upon returning to Sofia, Mr Passy enquired what the place was but never received a conclusive answer.

Strictly no entry

Through the years there have been rumours that businessmen from the Gulf were interested in buying the property and turning it into a luxury resort. The Bulgarian government did not agree to a deal.

If you start digging, metaphorically speaking, around the mysterious Object 17, you will soon discover that the more you think you find out, the less you actually know.

Let us start with the impressive ruins of the hotel that almost always accompany media articles, YouTube videos and Facebook posts about Object 17. In actual fact, the ruins are not near Lesidren. They are by another village in the region, Shipkovo. There, according to declassified documents, Object 3919 was located.

Decision B No. 26, issued by the Secretariat of the Central Committee of the Bulgarian Communist Party on 5 December 1978, declares that a balneotherapy sanatorium was to be built by Shipkovo's mineral springs and "to be utilised for the deployment and operation of the Central Committee of the BKP apparatus under wartime conditions." The construction of a new road between Shipkovo and Etropole, on a pass crossing the Stara Planina and providing easy access to Sofia, was ordered. The document describes the specifications of the underground facilities: "The primary facility was to be of a gallery type, with a protection rating of 50 kg per sq cm against the shockwave overpressure from a 1 megaton nuclear blast, as well as against a direct hit from a nuclear strike of up to 50 kilotons and a 1,000 kg high explosive aerial bomb. The capacity of the main protective structure was to accommodate approximately 300 operational personnel. A computing centre was also to be established within it." There were to be radio facilities as well. The object's costs were not to exceed 50 million leva, estimated at 100-300 million euro today.

It is easy to find Object 3919 on Google Maps (42°53'4"N, 24°31'19"E), and its distinctive structure is clearly visible in aerial view. There are plenty of photos of it, including ones taken by drones, but all of them are from outside the building. Access to the site is forbidden.

A crumbling checkpoint still guards the Lesidren site

No one has ever produced verifiable coordinates of the mysterious Object 17. A YouTuber has listed the location of the site's supposed gate post and the main facilities. But these are even farther from Lesidren. They are south west of Etropole and are close to the location of Object 2211, a site that, according to users of Bulgarian Wikimapia, was "the main command and evacuation point of the state's political and government elite. A military unit with the highest level of secrecy."

Unlike Object 3919 and like the mythical Object 17, Object 2211 is deep in the mountains. The government chose the location and approved its construction in the late 1950s. In the following 20 years it, according to Wikimapia users, became "the largest and best equipped underground compound in Bulgaria. There were several levels. Due to its security level, people of Etropole dubbed it The X. It could shelter 300 people for up to one month." When you enter the coordinates on Google Maps, 42°47'35.0"N, 23°56'40.0"E, you will see only forest.

Google Maps is of no help if you decide to manually search for the large abandoned structure of Object 17 somewhere around Lesidren. And when you track the earliest reports about the site on the Internet, which date back to 2014, you will find that they do not mention a fake hotel at all. Instead, they talk about the sudden discovery of an expansive underground system built under Communism. Mr Passy's account is already present in these early sources.

In the years that have passed since 2014, Object 17 has morphed into yet another story about hidden treasures, bombs or wisdom that are so popular in Bulgaria. The biggest of these are the stories of the mythical gold of Valchan Voyvoda, the so called Tomb of the Egyptian Goddess Bastet in the Strandzha and the supposed burial site of an extraterrestrial in Tsarichina. Valchan Voyvoda's stories have been around for at least two centuries. Bastet and Tsarichina appeared in the turbulent times of the 1990s, spread by the budding sensationalist media and press that mushroomed after the collapse of Communism.

The story of Object 17 is the fruit of the Internet age. With each iteration, it has obtained new details, absorbing information about similar sites, until it became an emanation of the omnipresent Bulgarian belief that the government is always eager to spend large sums of public money on obscure projects and that citizens will never get a clear idea of how vast the deep state is.