|Location||Mayflower, Louisiana, Tensas Parish, Louisiana, USA|
|Region||Tensas Parish, Louisiana|
|Cultures||Coles Creek culture|
|Responsible body: private|
Sundown Mounds is an multimound archaeological site in Tensas Parish, Louisiana from the Early Coles Creek culture. It is the type site for the Sundown Phase (600-800 CE) of the Tensas Basin and Natchez Bluff Coles Creek chronology.
The site is located on the western bank of Little Choctaw Bayou and has three platform mounds that form a triangle surrounding a plaza, a typical Coles Creek arrangement. Mound A, the largest mound, is a 11 feet (3.4 m) in height and its base measures 190 feet (58 m) by 180 feet (55 m) and a summit measuring 60 feet (18 m) by 60 feet (18 m). Mound B, the second largest, is located 400 feet (120 m) to the northwest of Mound A. It is 8 feet (2.4 m) in height with base measurements of 130 feet (40 m) by 100 feet (30 m) and its summit 65 feet (20 m) by 33 feet (10 m). Mound C is 7 feet (2.1 m) with base measurements of 100 feet (30 m) by 80 feet (24 m) with a dome-shaped summit. Mounds A and B had ramps from their summits down to the plaza. The mounds were constructed sometime between 750-800 CE, but the site was occupied during most of the Coles Creek period from 700 to 1200.
- "Indian Mounds of Northeast Louisiana:Sundown Mounds". Retrieved 2011-10-21.
- Kidder, Tristram R. (1998-10-28). "Mississippi period mound groups and communities in the Lower Mississippi Valley". In Lewis, R. Barry. Mississippian towns and sacred spaces: searching for an architectural grammar. University Alabama Press. p. 137. ISBN 978-0-8173-0947-3.