Cu Chi Tunnels among the world's strangest underground destinations

The complex tunnel system of more than 320 km long with full facilities serving life during the war in South Vietnam has amazed international tourists.

Cu Chi Tunnels, Vietnam:This unique attraction is located more than 30 km from Ho Chi Minh City and was built during Vietnam's resistance war against the French. Photo: Lesrivesexperience.

The complex tunnel system, which is more than 300 km long, had enough living quarters, hospitals, supply lines and warehouses to support life during the war. The narrow entrance, once hidden under a carpet of fallen leaves, has now been widened so that visitors can explore inside. Photo: Visa2vietnam.

Catacombs of Paris, France:This is where the remains of more than 6 million people who died between 1785 and 1860 are kept. These bones are separated and arranged into corridors, doors, columns... Photo: Smithsonianmag.

The 300-kilometer network of ancient caves, tunnels and deep chambers, most of which are filled with human bones, is mostly visited by day, but the catacombs have rooms for two brave enough to spend the night.

Bounce Below, Llechwedd Mine, North Wales:The world's largest trampoline park is located in a giant cave at Llechwedd Mine, Blaenau Ffestiniog, with three giant trampolines for visitors to enjoy. Photo: Thisiscolossal.

You can get to Bounce Below by train. However, each trampoline is next to a 60-foot slide suspended over a deep abyss. So this place is not for those with a fear of heights. Photo: CNN.

Salina Turda, Romania:This underground theme park is located in one of the world's oldest salt mines in Romania. These mines were dug by medieval people to mine salt. Photo: Businessinsider.

The Salina Turda mine is now an amusement park with a carousel, theatre, bowling alley, mini golf and underground lake. Photo: Cartitaplimbareata.

Cabinet War Bunker, London, England:The late President Churchill ran politics from this bunker during World War II, staying here overnight when advisers deemed it too dangerous to return to 10 Downing Street. Photo: Amylaughinghouse.

These rooms occupy only one-third of the 3,000-square-meter underground complex used in 1940-1945. Today, this place still preserves many interesting historical artifacts. Photo: Sightseeingtours.

Coober Pedy, Australia:Here, visitors will discover underground life, where more than 3,500 residents have built homes and many shops under the clay rocks of the Outback. Photo: Dailymail.

This underground town has houses, churches, museums, galleries, restaurants, bars, and even hotels for those who want to stay overnight. The houses here are fully furnished, from built-in wardrobes, fireplaces, and kitchens. Photo: Urbanpeek.

Salt Cathedral, Colombia:Located 180m below ground, this church is a marvel, with statues carved from salt and a giant cross in the centre. Photo: Famouswonders.

Now a tourist attraction, located in Nemocon, Cundinamarca, more than 90 km from the capital Bogata, the mine dates back 500 years and now welcomes around 3,000 visitors every Sunday. Photo: Paradiseintheworld.

Wieliczka Salt Mine, Poland:The Wieliczka Salt Mine is Poland’s largest tourist attraction, with hundreds of kilometres of tunnels. A sanatorium deep underground here is popular with asthma patients, thanks to its clean, unpolluted air. Photo: Thedailybeast.

In addition, there is also a chapel, ballroom, restaurant, shop..., all carved from monolithic salt rock. Photo: Grupafuntime.

The Vaults, London, UK:The Vaults hosts a variety of theatre shows, film screenings, golf and nightly events. Photo: Hirespace.

Located deep in the tunnels beneath Waterloo station, The Vaults Theatre has 176 seats with a classic, mystical atmosphere. It also has an art gallery and a kitchen for visitors. Photo: Vaultsbirmingham.

Located deep in the tunnels beneath Waterloo station, The Vaults Theatre has 176 seats with a classic, mystical atmosphere. It also has an art gallery and a kitchen for visitors. Photo: Vaultsbirmingham.

According to Zing.vn