The Kirkhead Tower

Since coming to Grange I have been wondering what the ruined tower was that is visible on the hilltop behind Kent's Bank and inland from Humphrey Head.  I finally got round to googling it and have discovered it is the Kirkhead Tower, an early 19th century summerhouse.  It lies within the Holker Estate and there is normally no public access.  It must have had great views from up there.