English: View across the Arminghall Henge Its outline is still visible in low light. In 1929 a prehistoric timber circle and henge monument site was discovered 1½ miles (2½ km) northwest of Arminghall village by Gilbert Insall VC who had been taking aerial photographs of the area in search of new archaeological sites. Whilst flying at around 2,000 feet (600 m) he noticed cropmarks of a circular enclosure made of two concentric rings with a horseshoe of eight pit-like markings within it. The entire site was around 75 m in diameter. The site was visited a week later by O.G.S. Crawford, who pronounced it to be the Norwich Woodhenge but it was not until 1935 that it was first excavated, by Grahame Clark. His work established that two circular rings were ditches, the outer one 1.5 m deep and the inner one 2.3 m deep, with indications of a bank that once stood between them. The pits in the middle were postholes for timbers that would have been almost 1 m in diameter. The site dates to the Neolithic, with a radiocarbon date of 3650-2650 Cal BC (4440±150) from charcoal from a post-pit. The henge is orientated on the mid-winter sunset, which, when viewed from the lication, sets down the slope of nearby high ground, Chapel Hill.