The Colour of Magic- Lock and Dam No. 7 (Wikipedia)
Lock and Dam No. 7 is a lock and dam located on the Upper Mississippi River at river mile 702.5 near the cities of La Crescent, Minnesota and Onalaska, Wisconsin. It forms pool 7 and Lake Onalaska. The facility was constructed in the mid-1930s and placed in operation on April, 1937. It underwent major rehabilitation from 1989 through 2002. The lock and dam are owned and operated by the St. Paul District of the United States Army Corps of Engineers-Mississippi Valley Division.
- Great A’Tuin (Wikipedia)
Great A’Tuin is the Giant Star Turtle (of the fictional species Chelys galactica) who travels through the Discworld universe’s space, carrying four giant elephants (named Berilia, Tubul, Great T’Phon, and Jerakeen) who in turn carry the Discworld. The narration has described A’Tuin as “the only turtle ever to feature on the Hertzsprung–Russell diagram”.