This is a monument to a former mine-owner, Baron Basset, in the Redruth area, located on the site of a neolithic monument. These days people come to visit the Castle restaurant which is apparently candle-lit as it has no electricity, serves up middle eastern food and a limited wine list (red or white house) and a drum beat serenade by moonlight.
We came here to look at the views and it was a great opportunity for me to test my knee out with a hill climb. If I make it to the restaurant I will review it. This is a great site with a fascinating history - see the wiki entry. It is great to get off the beaten track in Cornwall and this one track that meets that criteria.