An incredible new home for Surrey's sand martin population has been built at a nature reserve near Merstham.

The giant 20-metre wide sandcastle was built specifically as a home for sand martins at the Spynes Mere nature reserve close to Merstham in Surrey.

The sandcastle comprises of some 400 tonnes of sand, and will provide hundreds of new sand martin homes at the reserve for the first time in 25 years.

The project was backed by Surrey Wildife Trust (SWT), who pointed out that sand martin numbers in the UK are falling rapidly, hence the need for greater protection.

"Sand martin numbers have plummeted twice in the last fifty years as a result of droughts in their wintering grounds in Africa.

"In the UK, the natural nesting inland habitat along river banks has decreased as rivers pass through more urbanised areas and under roads, and quarrying has ceased," James Herd, project manager at SWT, said.

"So creating this nest bank is important to protect them against the boom and bust nature of their nesting sites and give more security for the population to expand.

"They are sociable birds that roost together in large numbers and so the scale of the sand bank is as important as its sustainability. Here at Spynes Mere the sand martins can return to nest year after year," he added.

Surrey Wildlife Trust worked with professional sand sculptors, Sand in Your Eye, to create the 20 metre long by 5 metres deep and 1.8 metre high structure from a giant bucket mould made from wooden boards.

Surrey Comet: Image: SWTImage: SWT

The nest bank has been built on a restored sand extraction site, which is part of the Nutfield Marshes complex of wetland reserves.

Land owners Sibelco meanwhile supported the conservation project by clearing the bank of scrub on the new nest bank site, as well as offering extra man-power, diggers and dumper trucks for the sandcastle build.

"New vertical faces carved out of the natural sandscape and the nest bank together provide 100 square metres for sand martin homes," SWT said.

"After five or six years, the sand can be recycled and the bank rebuilt so it provides a lasting home for the sand martins for the future," a spokesperson added.

The project was funded by a local growth investment fund, Coast to Capital, as part of the Naturally Richer project, and supported by Chessington World of Adventures Resort’s Chessington Conservation Fund.