The little church of St Michael de la Rupe sits atop a 335 metre high basalt tor called 'Brentor' near Lydford in West Devon. The rock is quite different from the Dartmoor Granite batholith which was intrusive, and was formed from lava which was extruded onto an ancient seabed 300 million years BP). The picturesque little church was started around 1130AD with its tower being added in the 1400s.