The Qattara Depression (Arabic: منخفض القطارة Munḫafaḍ al-Qaṭṭārah) is a depression in the north west of Egypt in the Matruh Governorate and is part of the Western Desert. It lies below sea level and is covered with salt pans, sand dunes and salt marshes.
Overall, the risk of sinkholes occurring in Guatemala City is high and unpredictable. One recent, similar sinkhole had collapsed in 2007, forming a pit 100 metres deep. The 2007 Guatemala City sinkhole was formed by fluid from a sewer eroding uncemented volcanic ash, limestone, and other pyroclastic deposits underlying Guatemala City.
The Umpherston Sinkhole (or the Sunken Garden) is one of the most spectacular gardens located in the Mount Gambier region. Umpherston sinkhole was once a typical limestone cave that formed by the corrosion of limestone rocks by seawater waves and the sinkhole was naturally created when the chamber’s roof collapsed.
A dramatic sinkhole collapse measuring some 100 feet in diameter by 41 feet deep occurred suddenly in the Borough of Macungie on June 23, 1986. The sinkhole collapse resulted in a major disruption of traffic, utility services, as well as a major health and safety hazard.