A group of Neolithic chambered tombs, constructed around 3500 BCE in the Severn-Cotswold region of western England and south Wales, consists of precisely built, long trapezoid earth mounds covering a burial chamber: they are a type of chambered long barrow.
In some examples, pairs of smaller burial chambers lead off from either side of the central rectangular burial chamber, itself connected to an anteroom.
In others, the entrance is a false entrance with the burial chambers accessed laterally from directly outside.
A third group has merely a single large chamber.
Tombs of this type are concentrated in the Cotswolds but extend as far as Gower and Avebury with some isolated examples in North Wales.
Tombs of all three types are generally evenly distributed and it has been theorized that the design evolved over time.
Severn-Cotswold tombs share certain features with the transepted gallery graves of the Loire and may have been inspired by these, with the lateral chambers and other differences being local variations.
