The rivers of Sri Lanka originate in the central highlands. From there they descend to the plains and empty into the sea. The rivers are typically unnavigable in their higher reaches, where they flow swiftly and turbulently through highly eroded passages to the plains below. Many rivers descend over steep cliffs, forming spectacular waterfalls. In their lower courses, the rivers slowly meander through flood plains and deltas.
The natural vegetation of Sri Lanka varies according to climatic zone and elevation. Dense evergreen rain forests are found in the southwestern lowlands. Trees include mahogany and many varieties of palm, including coconut, betel, and palmyra. In the central highlands, montane evergreen forests are interspersed with grasslands. The drier evergreen forests in the north and east contain trees such as ebony and satinwood. Thorn forests and drought-resistant shrubs prevail in the driest areas. Along the coast, mangrove forests border lagoons and river estuaries. Screw pines and palm trees also grow in coastal areas. A variety of water hyacinths, ferns, acacias, and orchids are found in many areas.
The animal life of Sri Lanka includes 88 species of mammals, 21 of which are threatened with extinction. The Asian elephant, cheetah, leopard, and several species of monkey are endangered and officially protected. The islands many species of primates include the long-tailed langur, toque macaque, and slender loris. Other mammals include the sloth bear, several species of deer, mongoose, and wild boar. Reptiles are numerous, with 144 known species. Some are threatened with extinction, including all five of the islands marine turtle species. Snakes include the cobra, viper, and python.
Sri Lanka has one of the worlds most diverse frog populations, with more than 100 identified species. More than 400 bird species inhabit the island, some on a migratory basis. Many are colorful, tropical species, including the blue magpie, paradise flycatcher, flamingo, and parrot.
The ancient cities of Anuradhapura and Polonnaruwa contain some of Sri Lankas most renowned architectural treasures. Located in the north central region, these once-resplendent cities served as the capitals of Sinhalese kingdoms from the 300s BC to the AD 1200s. The ancient cities contain the ruins of numerous palaces and Buddhist temples, rock sculptures of the Buddha, and Buddhist memorial mounds called dagobas
Some of Sri Lankas standing Buddha rock sculptures are colossal in proportion. Among the tallest and best preserved is the Buddha in Aukana. A free-standing sculpture hewn from solid rock, it stands 13 m in height, including its carved lotus-petal pedestal. The ruins of Polonnaruwa include the rock temple of Gal Vihara, where a series of four large Buddha sculptures were cut from a granite ridge in the 1100s. The standing Buddha is 7 m tall, and the reclining Buddha is 14 m long. The rock temple of Isurumuniya Vihara, built in the 200s BC at Anuradhapura, is renowned for its rock carving of two lovers. The temple overlooks the Tissawewa tank, one of three ancient reservoirs in Anuradhapura.
Many of the paintings of the ancient kingdoms have been obliterated by the passage of time. The cave temples of Dambulla, however, contain brilliantly colored wall paintings depicting the arrival of Buddhism in Sri Lanka and other historic events. The frescoes of Sigiriya, a rock fortress built in the AD 400s, depict nonreligious images similar in form to paintings found in the Ajanta Caves in east central India. Sri Lankas many Buddhist relics, sculptures, and temples attest to the importance of the religion in Sri Lanka since ancient times. Among the most revered Buddhist relics are the sacred bo tree at Anuradhapura, dating to the 200s BC when the teachings of the Buddha were introduced, and a tooth believed to be that of the Buddha, enshrined in the Dalada Maligawa in Kandy.
The Sri Lankan tradition of folk drama includes the kolam, a masked drama, and the sokari and nadagam, stylized dramas with song and dance. Sinhalese classical dance includes the highly athletic Kandyan form, which originated in the central highlands when the region was part of the kingdom of Kandy from the AD 1500s to 1815. The Kandyan performances include representations in dance of animals and birds, as well as stories from the Ramayana, a Sanskrit epic of ancient India. The dances are accompanied by complex drum rhythms. Tamil classical dance includes bharata natyam, a highly stylized form that originated in southern India. Baila, a style of song and dance introduced by the Portuguese in the 1500s, is widely popular in Sri Lanka.