Triangle Park is a former American football stadium located in Dayton, Ohio. The stadium was home to the Dayton Triangles of the National Football League from 1920 to 1929. It had a capacity of 5,000 spectators. It was located at the confluence of the Great Miami River and Stillwater River. On October 3, 1920, it hosted the first NFL game against the Columbus Panhandles. Today, it is a park in the city of Dayton.