After the RailTrail, we went to Archbald Pothole. This shows me at the Pothole. Here's some of what the state park people say about this feature: "Archbald Pothole State Park is a 150-acre park in northeastern Pennsylvania. The park is named for Archbald Pothole, a geologic feature that formed during the Wisconsin Glacial Period, around 15,000 years ago. The pothole is 38 feet deep and has an elliptical shape. The diameter of the pothole decreases downward. The largest diameter is 42 feet by 24 feet. At the bottom it is 17 feet by 14 feet. The pothole has a volume of about 18,600 cubic feet, so could hold about 140,000 gallons. It would take 35 fire truck tankers to fill the pothole. "