Wikipedia is soliciting photos of US historic and cultural sites through September 2018, with prizes awarded for the best photos.

Subjects must be registered as a cultural or historical sites in the US. Contributions will be judged and cash prizes given.

Top ten photos selected by judges will each win first place prize of $500, and top 10 places will win cash or equivalent.
https://commons.wikimedia.org/wiki/C..._United_States