LITTLE is known of the tunnels that lie under various parts of Sofia. Built as bomb shelters during times of looming war, the tunnels are a mystery for both Bulgarians and foreigners, most of whom are unaware of their existence, much less their history. It comes as no surprise that the building that is now the President's Palace, and has been since the 1990s, boasts a bomb shelter. It was built in the summer of 1949 when a refuge was also built underneath the building of the Parliament, which is still the home of the Council of Ministers. The shelter in the President's Palace is still operating, but is now used as a training centre for the Civil Protection Agency to prepare for incidents of biological terrorism or the deployment of weapons of mass destruction. Once active during the Cold War to ensure the safety of the Communist elite, this shelter is now prepared to guarantee the safety of Bulgaria's democratic leaders.

The existence of such a bomb shelter is not a rarity for any well-organised state. It is the history and existence of Sofia's mysterious tunnels that is intriguing. The mausoleum of former Bulgarian prime minister and Communist Georgi Dimitrov, contained an entrance to a tunnel that runs under Tsar Osvoboditel Boulevard and connects to the Council of Ministers. The mausoleum, a copy of Lenin's in Moscow, was a sore spot in Bulgaria's transition to democracy, and was destroyed - after six attempts - in the late 1990s. It was in this tunnel that the former Communist Party leaders were meant to hide in the event of an all-out war. Able to hold between 250 and 300 administrative personnel, this tunnel has remained a well-kept secret from the vast majority of Bulgarians.

At the base of the hill in South Park are the entrances to a series of tunnels built by the Germans before the start of WW2. At 2m 50cm tall and able to hold up to 1000 people, these tunnels are referred to as galleries because they include a number of separate rooms, enabling them to hold more people. These bomb shelters were actually used during the war, when the American forces and its Allies were bombing Bulgaria. Many people died during this time, as the buildings themselves were not strong enough to sustain such a barrage of weaponry. Without emergency exits through which to escape, much less a sturdy building to hide in, those who did not seek shelter in the underground tunnels suffocated under the debris of demolished buildings. Ironically enough, when the new American Embassy in South Park was constructed in 2004, one of the newest, state-of-the-art bomb shelters was built underneath it.

The tunnels, or "galleries", at the bottom of the hill in South Park remained in relatively good condition until the 1950s, when they were abandoned. The cement and negligible amount of bricks that comprised the structure of these tunnels began to disintegrate, and without the proper funding to maintain them, they began to crumble and fill with water. The water was drained when apartment complexes were built on the hill, but the tunnels remain damp. Between 1989 and 1993, all of the supplies that had been stored in the galleries were stolen. Drug addicts would gather inside the dark passageways, and kids would play inside the hollowed-out earth. Because of their dangerous state and the difficulty in navigating these tunnels, they were padlocked and sealed off with iron gates; no one was allowed to enter.

Most of the buildings built in the post-WW2 era contain underground bomb shelters. In 1972, many new apartment blocks were erected, and it was standard for them to have shelters underneath. However, after this time, new regulations and laws specified the safety levels required to build such shelters, and contractors and building companies opted not to construct them due to the increased concrete requirements, the need for special equipment, and the regulation of the depth. For over 15 years, bomb shelters have not been built in apartment blocks.

Another difficulty facing the engineering and construction of underground structures in Sofia is the large number of underground streams that run through the city. There was a rather significant one running along the President's Palace and under Tsar Osvoboditel Boulevard when the bomb shelters were being constructed, but an attempt was made to drain it. Concrete was placed around the stream in order to isolate it, but it remains wet. Similar problems are occurring with the construction of the Metro system that will run through the heart of the city's centre. 

With all the hustle and bustle going on above ground, the mysterious structures underground have been forgotten. Once constructed to ensure the safety of Bulgaria's rulers, they remain for the most part unused and neglected, decaying relics of a forgotten era.