: Hello, my sister recently purchased a colonial on 3 lots. After the lawn was cut, we recently noticed a black thin plastic 2 inch pipe, with a bell or flanged, or flared top, kinda like a donut shape at the top of it. It is about 40 feet away from the house and about 3 feet from the sidewalk and is flush with the ground. It appears to be open, ie. not clogged as you can see down a little. What is this thing?