Castle green dates to the 6th century and has the Nelson Column on it. This burial ground was used both by the monks and by the civilian population of Hereford. As many as 15,000 bodies may lie buried beneath Castle Green. Around AD 550 a monastic community started at Castle Green long before Hereford existed. This site was created to celebrate to St Guthlac who died in AD 715. When St Guthlac's tomb in Lincolnshire was destroyed, some of his relics made their way to Hereford.