The Stelling van Amsterdam was the most advanced military structure of its type in the world – 135 km (84 miles) of forts, batteries and moats completely encircling the city in a defensive barrier.
Spread across the beautiful rolling hills of Rakhine in Western Burma, lies a little known archeological site—the medieval town of Mrauk U.
The norias of the ancient Syrian city of Hama are seventeen historic waterwheels located along the Orontes River that date back to the Byzantine Era.
Some 3,000 driving dams once existed throughout New Zealand, with the last built during the late 1930s. As the timber industry dwindled, gradually the dams decayed and disappeared and now only a few remain as relics of this destructive industry.
On the Maryland side of the Potomac River just west of Chesapeake Bay, the largest shipwreck fleet in the Western Hemisphere sits half-sunk and decomposing.
The Kola Superdeep Borehole was a scientific project undertaken by the Soviet Union in the 1970s to better understand the Earth’s crust.
Danish artist Thomas Dambo has been building stuff using trash and recycled materials since an early age, starting with smaller sculptures such as birdhouses and furniture to bigger pieces such as the six “Forgotten Giants” he recently installed around Copenhagen.
The Stone Forest or Shilin is a notable set of limestone formations about 500 km2 located in Shilin Yi Autonomous County, Yunnan Province, People’s Republic of China, near Shilin approximately 90 km (56 mi) from the provincial capital Kunming.
Derinkuyu Underground City is an ancient multi-level underground city of the Median Empire in the Derinkuyu district in Nevşehir Province, Turkey.
In 1948, a top-secret biological weapons laboratory, nicknamed Aralsk-7, was established here. Until its closure in the 1990s, the laboratory tested some of the deadliest pathogens known to man, including plague, anthrax, smallpox, brucellosis, tularemia, botulinum and Venezuelan equine encephalitis.
SS Richard Montgomery was an American Liberty ship built during World War II, one of the 2,710 used to carry cargo during the war.
Five meters below the runway of Sarajevo’s airport runs a short stretch of tunnel that was dug out during the Siege of Sarajevo to bring supplies to the cut-off city. For four years this 800-meter long tunnel was the besieged city’s only connection to the outside world, and its life support.
Some 250 million years ago, a part of Ukraine was under a shallow ocean. When the ocean dried up, it left behind a huge deposit of salt.
The Great Barrier Reef is the world’s largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 kilometres.
Mù Cang Chải is a rural district of Yên Bái Province, in the Northeast region of Vietnam. As of 2003, the district had a population of 42,574. The district covers an area of 1,199 km². The district capital lies at Mù Cang Chải.
Pamukkale, meaning “cotton castle” in Turkish, is a natural site in Denizli Province in southwestern Turkey. The city contains hot springs and travertines, terraces of carbonate minerals left by the flowing water.
The Borovsko Bridge is an unfinished highway bridge near Borovsko , part of Bernartice municipality, Central Bohemian Region, Czech Republic. It is commonly known as the “Czech Avignon” or “Hitler’s Bridge”.
Situated in the west of Bosnia on the border with Croatia, Objekat 505, as it was officially known, was the largest underground airport in the Balkans. The primary purpose of the Objekat 505 was to house a long-range radar early warning system, akin to NORAD, as well as to provide a strategic command center for the country’s defense.
The Kelvedon Hatch Secret Nuclear Bunker at Kelvedon Hatch, in the Borough of Brentwood in the English county of Essex, is a large underground bunker maintained during the cold war as a potential regional government headquarters.
Mar Sem Fim (“Endless Sea” in English) is a Brazilian yacht that was shipwrecked, sunk and subsequently got frozen in ice in Maxwell Bay of Ardley Cove, Antarctica.