A distinctive feature of the Thames and Severn Canal is the roundhouse. There are five of these in total which are located at:

1. Chalford
2. Coates
3. Cerney Wick
4. Marston Meysey
5. Inglesham (Lechlade)

These were constructed within 2 years of the canal's opening in 1789 and served as lengthsman's cottages.

The roundhouses came in two basic forms. One with a conventional pitched roof, the other with an inverted 'conical roof'. The inverted roof is believed to have been used to collect rain water to supply the roundhouse.

Chalford & Cerney Wick have the conventional pitched roof, while the roundhouses at Coates, Marston Meysey & Lechlade have the inverted roof.

The roundhouses have three floors. Originally the ground floor would have been used as a stable with the first and second floors being used for living accommodation.