Ice aided construction of Forbidden City
Workers slid heavy stones on paths covered with liquid and frozen water
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2013/11/chinapalace_icepaths_free.jpg?fit=860%2C460&ssl=1)
Artificial ice paths probably helped Chinese workers slide heavy stone, such as this 300-ton marble carving, into the Forbidden City in Beijing, China, when the site was built in the 15th and 16th centuries.
Courtesy of Chui Hu