Area: 0.36 hectares.

Description and Reasons for Notification: 

This locality shows Middle Devonian grey slates, which have yielded a diverse macrofauna of Eifelian age (middle Devonian, 392 to 398 MYA). This is the best inland exposure of this facies in Cornwall and Devon and is, by far, its most important fossiliferous locality. Rosenun Lane is a key site in interpreting the Middle Devonian palaeoecology of the region.