If it's for excess water runoff, it's likely a brick or block structure filled with gravel. Over time, it will often silt up and be ineffective or later homeowners choose another approach to diverting excess water.

Beware though, that the pipe might also be leading to a graywater dry well, seepage pit, or cesspool. If you plan on disturbing it, it would be worthwhile to have a pro take a look first.

If it's for excess water runoff, it's likely a brick or block structure filled with gravel. Over time, it will often silt up and be ineffective or later homeowners choose another approach to diverting excess water.

Beware though, that the pipe might also be leading to a graywater dry well, seepage pit, or cesspool. If you plan on disturbing it, it would be worthwhile to have a pro take a look first.

"I assume these are some type of drywell."

Or a drainage path to either a dry-well or daylight.

Dry-wells should be a distance from a basement or foundation.

Dry wells sometimes are under the house if they were designed to store rain water collected via gutters for household use.

I've got a lovely, round, double-thick, brick-sided one under what used to be my kitchen. It supplied the pitcher pump and dry sink as recently as 1959. Mine is eight feet in diameter and six feet deep.

It's dry as bone these days as the gutters lead elsewhere, now.

I'm in northern NY in a pre-Civil War farm dwelling.

L.