"Springbox" is what it is, thanks Ranger I termed that wrong. The hole is round and about 3 feet across, perfect size to cover as you mentioned. Right beside this spring, is a now fallen ancient beech tree that was easily several hundred years old and was literally covered with the carvings of dozens of couples and individuals who had left their mark in the 1800's-early 1900's. Always fills me with wonder to observe the now heavily underbrushed hillside and imagine the workday dinners, social gatherings, laundry, baths and who knows what else that took place between and around that tree and the spring. I was blessed years ago to be visited by a 96 year old woman(and her son) who's father built my house. One of the first things she ask me was if the tree and spring were still there. Was glad to say yes. The tree was struck by lightning and has since died and fallen. Glad the springs still pumping. J