This is the Washington side of the Bonneville dam and hydro power unit. This is relatively new compared to the Oregon side. Inside there are multiple levels to see. One of the buildings on first floor has educational content and generator viewing area. There is a theatre which play the history when it is open. The ground floor has access to fish ladders. All places have elevator access. There are tours at certain times a day and well worth it. It is about 45 minutes and they take you close to one of the generators to explain its working. Staff are generous and always ready with answers when needed.