The Longyou Caves were only discovered late in the 20th century. At least 24 caves have been discovered so far. All of which were carved by hand. Although the overall excavation involved almost a million cubic metres of stone, there is no historical record of them or evidence of the work. Their origin is a complete mystery. At present there is no explanation for their existence. They represent one of the largest underground excavations of ancient times.:
The Longyou Caves. Discovered in 1992, no historical record or evidence of the work involved to excavate the almost million cubic meters of stone exists. The chiseling was done in such a way that it left a consistent pattern throughout the caves which some experts believe to be symbolic.There is also a rumor that seven of the caves have a distribution pattern that matches the seven stars of the Big Dipper.
Benmore Dam is the largest dam within the Waitaki power scheme, located in the Canterbury Region of New Zealand's South Island. There are eight other power stations in the Waitaki Power Scheme. The dam is the largest earth-filled water-retaining structure in New Zealand. Lake Benmore has a volume of 12.5 million cubic metres, about 1.5 times as much water as Wellington Harbour. The dam's spillway can cope with 3,400 cubic metres of water per second, about 10 times the mean river flow.
“The World Health Organisation (WHO) says there should be no human exposure to more than 200 micrograms per cubic metre (ug/m3) in any hour. But many places in London have dozens or hundreds of such exceedances every year. Putney High Street suffered a lung choking 1,151 exceedances in 2016.
The Akashi Kaikyō Bridge, also known as the Pearl Bridge, links the city of Kobe on the mainland of Honshu to Iwaya on Awaji Island, in Japan. It crosses the busy Akashi Strait. It carries part of the Honshu-Shikoku Highway. #japan#hyogo