That Roundhouse is a roundhouse sited in woods within the Pembrokeshire Coast National Park near the town of Newport in Wales. It was constructed without planning permission during the winter of 1997/1998 by Tony Wrench and Jane Faith and helpers as part of the then secret Brithdir Mawr intentional community. The structure was discovered in 1998, challenged by the authorities, and threatened with demolition; it was granted retrospective planning permission in September 2008, with a review in three years.