ODESSA, Ukraine--The Odessa Catacombs, a labyrinth-like network of tunnels (subterranean cavities) located under the city of Odessa and its outskirts in Ukraine, consisting of a network of basements, bunkers, drainage tunnels and storm drains as well as natural caves, on three levels and reach a depth of 60 metres (200 ft) below sea level, running up to 2,500 kilometers (1,600 mi), sets the world record for being the World's largest urban labyrinth (largest network of tunnels), according to the WORLD RECORD ACADEMY.
Photo above: Map by http://katakomby.odessa.ua via Atlas Obscura
"With more than 2,000 kilometers (1,243 miles) of tunnels, this underground city is so vast and complicated -- there are at least 1,000 known entrances -- that tourists are advised not to enter without a qualified guide,"the CNN Travel reports.
Parts were used as air-raid shelters during World War II. Part of the tunnels, only under the city, were turned into bomb shelters in the Cold War. Such bomb shelters supposed to be refuge for civilians in case of nuclear strike or gas attack.
Photo above: Trip Advisor/Catacombs of Odessa
Only one small portion of the catacombs is open to the public, within the "Museum of Partisan Glory" in Nerubayskoye, north of Odessa.
Other caves attract extreme tourists, who explore the tunnels despite the dangers involved. Such tours are not officially sanctioned because the catacombs have not been fully mapped and the tunnels themselves are unsafe.
The Odessa Catacombs are the largest network of tunnels anywhere in the world.
They’re significantly longer – and more complex – than the famous catacombs found beneath Rome (300km) and Paris (500km).
Photo above: YouTube/ The Odessa Catacombs
"Many tourists visit the ‘Museum of Partisan Glory’ at nearby Nerubayskoye, where there’s a kilometre-long section of catacomb neatly arranged with period-costume dummies and rusty WWII weapons,"the Ex Utopia reports.
During the WWII, when the Nazis arrived in Odessa, "the Soviets left key strategic units positioned beneath the city. These Ukrainian partisan groups hid deep within the catacombs, from where they continued to launch surprise attacks on the fascist forces."
Many tourists now visit the ‘Museum of Partisan Glory’ at nearby Nerubayskoye, where there’s a kilometer-long section of catacomb neatly arranged with period-costume dummies and rusty WWII weapons.
Photo above: Alk3R Post
"When the Nazis arrived in Odessa and began massacring the city’s population, the catacombs served as hiding place for Soviet partisans fighting the axis forces, the Alk3R Post reports.
"The hideouts were turned into comfortable living spaces by the guerilla fighters. There were recreation rooms where men played checkers, chess, or dominoes by candlelight. Rooms for accommodation had shelves cut into the walls where men and women slept. Kitchens were equipped with stoves made of limestone and smoke was vented into empty chambers above. There was even a hospital and an operating theater."
(* according to "The Culture Trip)
"Dating back to the start of the 18th century, Quarry Cantacuzene museum (or Quarry Kantakuzin), which is separate to the Secrets of Underground Odessa museum, is also worth exploring, the CNN Travel reports.
"As the oldest underground quarry in Odessa, it offers an interesting introduction into the world of the catacombs, as well as the early history of the city.