Mosaic made with 26,000 shells restored in 'once in a lifetime project' inside Exmouth house

• Watch Richard Lawrence's report

A mosaic gallery made with 26,000 shells have been restored in a 'once in a lifetime project' in Devon.

The conservation work was carried by the National Trust to restore the sixteen-sided house called A La Ronde near Exmouth.

The home was built in 1795 for two cousins - Mary and Jane Parmenter - and showcases a brave collection of wedge-shaped rooms and extraordinary design.

But, it's the shells gallery that sits high above the hallway that is the crowning glory of the unique building.

Kate Berlewen, a Conservator from the National Trust said: "The shell gallery is one of the oldest parts of the house. It has survived so well to this point we have to give it its due.

"The layers of the shell are actually very fragile. We think of shells as being robust and hard but actually over time they can become really powdery and brittle and break very easily, so we do have to be very careful with them."

Shells were an important part of 18th-century design and were a way in which woman could express their creativity.

The shells were mounted on line-based plaster, along with thousands of feathers that were also restored as part of the project, to create intricate patterns on the walls and ceilings.

Kate continued: " We're so lucky that it's survived because it is so fragile. The feathers and the glue holding it in place are 200-years-old.

"Being able to go round and not only clean the feathers but stabilise them is a privilege - a once in a lifetime project."