Clotted cream, Riviera-style coastline, and the picturesque expanse of Dartmoor are just a few of the things more usually associated with Devon. An octagonal Byzantine basilica is something that is most definitely not, but apparently that is what inspired this curious little round house to be built overlooking the river estuary at Exmouth.

Built at the end of the 18th century, A La Ronde was the home of two spinster cousins, Jane and Mary Parminter, who had spent 10 years touring the continent and enjoying the inspirational architecture of great churches, castles and monuments in at least six different countries. During this extensive vacation they collected a vast array of souvenirs and, once settled back in England, wanted an exotic home in which to display their foreign mementoes.

Who actually designed A la Ronde seems a little unclear but some evidence suggests that it was probably the brainchild of a very young John Lowder, a distant relative of Mary Parminter. The result was a most unconventional, 16-sided cottage, originally sporting limewashed walls and a vast thatched roof, and at that time was flippantly referred to as a 'South Seas Island' hut. Inside a series of peculiar wedge-shaped rooms on one level were created around a central octagon rising to 35ft (10.6m).

Today the appearance of A la Ronde, both inside and out, has changed quite dramatically. Dark red tiles, pierced with dormer windows, have long since replaced the thatched roof, and the limewash has been removed to reveal the original limestone blocks studded with their extraordinary diamond-shaped windows. Inside, the immense attic area was transformed with a second level of rooms being created, new windows were inserted in the ground floor walls, and an unwieldy central heating system was installed.

Despite these attempts to impress with a standard of Victorian modernisation, nothing really prepares the visitor for the wondrous spectacle of the shell gallery, a sight which highlights the undeniable skills of these two Georgian ladies. Millions of shells, feathers, stones and bits of pottery have been laboriously pressed into the walls to create a fanciful display almost beyond belief. Years of tireless, and often precarious, work must have gone into this fantastic exhibition of such delicate skills, and in an effort to preserve it for many more years to come, it is now only possible to view the work on closed circuit television.

Maybe the Parminters could be considered slightly eccentric, and from the Will left at Mary's death this might endorse that statement still further. She insisted that A la Ronde and its contents should be preserved intact, and that only unmarried ladies would be eligible to inherit it. These conditions held firm until the house was transferred to the Reverend Oswald Reichel, a brother of one of the former occupants, and it was Reichel who was responsible for the structural changes. In over two hundred years Reichel has been the sole male owner of this charming little cottage and, ironically, has made the most impact on A la Ronde's structural character.