It's Still There...

Bury Down [hillfort], Lanreath, is believed to have been originally constructed as a Neolithic causewayed enclosure, which was then reused as an Iron Age hillfort.

​http://www.heritagegateway.org.uk/Gateway/Results_Single.aspx?uid=MCO6594&resourceID=1020

Photo and text from Cornwall and Isles of Scilly Historic Environment Record​​