The unique feature of this park is the existence of "Willus" (Natural lakes) - natural sand-rimmed water basins or depressions that fill with rainwater. Located in the Northwest coast lowland dry zone of Sri Lanka, the park is located 30 km west Anuradhapura and located 26 km north of Puttalam. Nearly sixty lakes (Willu) and tanks are found spread throughout Wilpattu and it is the largest and one of the oldest National Parks in Sri Lanka. It is also among the top national parks & world renowned for its Leopard (Panthera pardus kotiya) population. In addition, 31 species of mammals have been identified within Wilpattu national park. Mammals that are identified as threatened species living within the Wilpattu National Park are the Elephant, Sloth bear, Leopard and Water Buffalo. Sambhur, spotted deer and mongoose are more of Wilpattu's residents.