The Thung Yai Naresuan Wildlife Sanctuary (, ) is a protected area in Thailand in the northern part of Kanchanaburi Province and the southern part of Tak Province. It was declared a wildlife sanctuary in 1972, and a World Heritage Site by UNESCO in 1991 together with the adjoining Huai Kha Khaeng Wildlife Sanctuary. Location and topography The sanctuary is at the western national border of Thailand with Burma, in the southern area of the Dawna Range. It extends northeast of the Three Pagodas Pass from Sangkhla Buri District in Kanchanaburi Province into Umphang District in Tak Province. The wildlife sanctuary stretches over an area of 2,279,500 rai ~ , and is the largest protected area in Thailand. Together with the adjoining Huai Kha Khaeng Wildlife Sanctuary () it constitutes the core area of the Western Forest Complex, which represents the largest agglomeration of contiguous protected area in mainland Southeast Asia, . Management of this wildlife sanctuary is split between two protected areas regional offices: PARO 12 (Tak) manages the west part and PARO 3 (Ban Pong) manages the east part of this wildlife sanctuary. Thung Yai Naresuan West Wildlife Sanctuary, 1,331,062 rai ~ Thung Yai Naresuan East Wildlife Sanctuary, 948,438 rai ~ The area is predominantly mountainous and composed of various limestones interspersed with massive intrusions of granite and smaller outcrops of quartzite and schist. Elevations range from about at the Vajiralongkorn Reservoir in the south of the sanctuary to its highest peak, Khao Tai Pa, at . Major rivers are the Mae Klong and the Mae Chan which originate in the Umphang Wildlife Sanctuary and join in Thung Yai into the Upper Khwae Yai which feeds the Si Nakharin Reservoir. Various smaller rivers in the south and southwest feed the Vajiralongkorn Reservoir while in the northwestern part of the sanctuary the Mae Kasat and the Mae Suriya flow into Burma. Climate and rainfall The climate of the region is characterised by three seasons: a hot, wet season from May to October, a cooler, dry period from November to January and a hot, dry season from February to April. Average minimum and maximum daily temperatures range from in the wet season, in the hot, dry season, and in the cooler season. Day-time temperatures can exceed in April, while nighttime temperatures of are not uncommon in the cool season. The average annual rainfall decreases from the western part of the