Heritage sites, such as the Padmanabhapuram Palace, Hill Palace, and Mattancherry Palace, are also visited.
The backwater network includes large lakes such as the Ashtamudi Lake, the largest among them, linked by 1500 km of canals, both man-made and natural and fed by several rivers, and extending virtually the entire length of Kerala state.
Other popular attractions in the state include the beaches at Kovalam, Kappad, Cherai and Varkala; backwater tourism and lake resorts around Ashtamudi Lake, Kollam; hill stations and resorts at Munnar, Wayanad, Nelliampathi, Vagamon and Ponmudi; and national parks and wildlife sanctuaries at Periyar, Parambikulam and Eravikulam National Park.
The "backwaters" region—an extensive network of interlocking rivers, lakes, and canals that centre on Ashtamudi Lake, Kollam, also see heavy tourist traffic.
The wildest lands are covered with dense forests, while other regions lie under tea and coffee plantations (established mainly in the 19th and 20th centuries) or other forms of cultivation.
The Western Ghats rise on average to 1500 m elevation above sea level.
The backwaters were formed by the action of waves and shore currents creating low barrier islands across the mouths of the many rivers flowing down from the Western Ghats range.