Visiting the Powerhouse was our favorite activity on the day we spent in Folsom. It's in a scenic location on the banks of the American River, and close enough to walk to the historic downtown where there are some other small museums and restaurants. The visitor center is modern and attractive with easy-to-understand displays that explain how hydroelectric power is generated and show the history of the facility. Admission is free (donations accepted) but there is a fee to park (free parking available nearby to the south). The old equipment in the powerhouse was fascinating - it felt like we stepped back in time - and the docents were friendly and very knowledgeable. Wheelchair access on the grounds was okay with some assistance; there were some unpaved areas and grades. Note that this attraction is only open noon to 4 pm and is closed Monday and Tuesday.