Robert Macfarlane is on his travels in various worlds beneath our feet.

On the Italian-Slovenian border he goes underground with the guide Sergio. Underneath the Karst, that is, where:

"a path winds down past blocks of limestone, to a brick hut. The hut is built over the entrance to the abyss..."

Read by the author.

Abridged by Katrin Williams.

Producer Duncan Minshull.

First broadcast on BBC Radio 4 in May 2019. Show less