Vessagiri, or Issarasamanarama, is an ancient Buddhist forest monastery that is part of the ruins of Anuradhapura, one of the ancient capitals of Sri Lanka. It is located about half a mile south of Isurumuniya, among boulders. Begun in the reign of King Devanampiya Tissa (mid-3rd century BC), the site was expanded during the reign of King Kasyapa (473 – 491 AD) to become home to about five hundred monks.