Found.

One of our search dogs finding me at the Amberley site.

Amberley Chalk Pits Museum

A couple of week back we were very lucky to be able to train at Amberley, it was closed to the public and although there were a few people working there we had the whole place pretty much to ourselves.
It made for a different type of search as there were buildings and porta cabins as well as wooded areas, I think we all enjoyed it even if we were covered in chalk when we left!
There was also the odd run in with a spook or two!