Qanat are underground water channels developed during ancient times to carry water using gravity via a gentle downward slope.
Ever wonder what happens to satellites and other space debris that make it back to Earth? The spacecraft cemetery is home to spacecraft, freighters, satellites, and space stations that have been retired from their jobs in space.
A transcontinental city is a city that exists on land over more than one continent. There are more than a few transcontinental cities in the world. Learn about cities that straddle continental divides.
World Wetlands Day is celebrated on February 2 each year. A wetland is an area of land that is covered with water at or near the surface either year round or for varying parts of the year.