The park spans the Eastern and North Central provinces in the deltoid plain of the Mahaweli Ganga.
It affords protection to a unique habitat, i.e. riverine villus and flood plains, as well as to the largest concentration of elephants in the country, in conjunction with the adjacent Flood Plains National Park. Although the area has been heavily exploited, regeneration will be rapid once human activity is phased out because of the abundance of moisture and high carrying capacity of the villus. Both parks are vital for migratory and resident waterfowl.
The park is most popular for the Somawathi Stupa which houses the left tooth relic of Buddha.
Sungawila is the last town and border village you come across on the route to Somawathi. After this town you come to the entrance of Somawathi wildlife sanctuary.
The park can be reached from Pollonnaruwa or from Minneriya. Coming from Minneriya, you have to pass the Higurakgoda town to reach Sungawila. From Pollonnaruwa, you need to turn at the Hospital Junction (between Pollonnaruwa and Kaduruwela towns). The distance to the stupa from both these towns (Minneriya and Polonnaruwa) is about 40 kilometres.