Archbald Pothole

This 38-foot deep hole within the borders of a state park bearing the same name is probably around 15,000 years old. The dimensions of the opening are 42 feet by 24 feet and it's said to have a volume of 140,000 gallons. It was formed by a glacier during the Wisconsin Glacial Period, perhaps carved out by a seemingly endless flow of meltwater. Finding and visiting the park is easy and you can look down the depths of the pothole from a conveniently situated viewing platform.