Udawalawe is undoubtedly the best place in Sri Lanka to see wild Asian Elephants throughout the year: there are about 500 elephants in the park and they often roam in herds of up to 100. Udawalawe National Park is unique in terms of consistency in numbers of elephants roaming the park: it has no a seasonal variation in herds of elephants. The best hours to visit the park are in the mornings and evenings. Late evening also affords the photographic opportunities in the backdrop of loveliest sunsets. Udawalawe has rich biodiversity. There are so many Species recorded from the park include 94 plants, 21 fish, 12 amphibians, 33 reptiles, 184 birds (33 of which are migratory), and 43 mammals. Additionally, 135 species of butterflies are among the invertebrates found in Udawalawe. 

Udawalawe lies on the boundary of Sri Lanka's wet and dry zones. Plains dominate the topography, though there are also some mountainous areas. The Kalthota Range and Diyawini Falls are in the north of the park and the outcrops of Bambaragala and Reminikotha lie within it. The habitat surrounding at the reservoir includes marshes, the Walawe river and its tributaries, forests and grasslands. In the six months ending in August 2009, the park earned revenue of Rs. 18.2 million. From 1994 to 2001 some 423,000 people visited the park, 20% of them foreigners. For the 1998-2001 period, average annual revenue was US$280,000. Postage stamps bearing the images of four wild animals of Udawalawe were issued on 31 October 2007 in the series "National Parks of Sri Lanka", featuring water buffalo, Sri Lankan elephant, ruddy mongoose and tufted grey langur.