UNESCO World Heritage Sites in Sri Lanka: whc.unesco.org/en/statesparties/lk -- Polonomaruwa, Sigiriya, Dambulla, Galle, Anuradhapura, Kandy, Sinharaja and maybe later Adam's Peak and Horton Plains.
RAMSAR Wetlands of International Importance: ramsar.org
Department of Wildlife Conservation: dwc.gov.lk