The Ness of Brodgar has been an incredibly important site. Twenty years of excavation have produced more objects and artefacts than the rest of the UK combined. But the buildings are deteriorating, so Matthew visits as the site closes to the public and the digger moves in to cover it back up.

Guests: With site director Nick Card and experts and volunteers Jo McKenzie, Antonia Thomas, Jan Blatchford, Anne Bevan, Sigurd Towrie and Jo Bourne.

It was incredibly moving to be at the site in its last days, and to be able to get down amongst the buildings before they were covered up. And watching the digger at work is something I’ll never forget.

Here are some of the things mentioned in the programme.

The incredible stonework of Structure 27, ‘the finest you’ll see in north west Europe’, according to Nick.

Before and after - the four metre thick wall, the digger at work, and the wall covered over.

Jan and Anne's milk ceremony with replica grooved ware pottery in Structure 12.

The carved stone ball from underneath Structure 10 and the butterfly design unique to the Ness in Kirkwall Museum. And the part of Structure 10 the ball came from.