Coolspring Power Museum - Open Days Experience history in motion at Coolspring Power Museum! Open one weekend per month from April through October, these special Open Days feature the normal operation of historic stationary internal combustion engines throughout the museum grounds. Home to the largest collection of historically significant early stationary internal combustion engines in America, the museum includes hundreds of engines displayed across more than 35 buildings and outdoor exhibits. Volunteers are often on-site to share insights about the engines and their role in early industry.  Located in Coolspring, PA on Route 36, halfway between Brookville and Punxsutawney  Open Days Hours: 10 a.m. – 5 p.m.  Admission: $12 Adults | Children under 12, Members & Volunteers – Free Special events throughout the season feature extended hours and unique programming. See individual event listings for details.