Mt. Kasuga Primeval Forest has been untouched for thousands of years. The forest stretches out across an area of half a kilometer, behind Kasuga Taisha Shrine. Logging and hunting have been prohibited here since AD 841 which has made it a rare ecosystem with over 175 types of trees, rare birds, insects as well as wild animals including the sacred wild deer that roam around central Nara during the day. At night the deer return to Kasuga Forest where they live. Kasuga Primeval Forest has been designated a UNESCO World Heritage site.