Kerala is a land of rivers and backwaters. Forty-four rivers cut across Kerala with their innumerable tributaries and branches. But these rivers are comparatively small and being entirely monsoon fed, practically turn into rivulets in summer, especially in the upper areas. The longest river is Bharatapuzha. The rivers are rich in associations regarding Kerala's tradition. Kaladi near Periyar was the birth place of the great Sankara.
Kerala has a continuous chain of lagoons and backwaters. Back waters form a specially attractive and economically valuable feature of Kerala. They include lakes and ocean inlets, which stretch irregularly along the coast. The biggest backwaters is the Vembanad lake some 200sq.km in area, which opens out into the Arabian sea at Cochin Port. The Periyar, Pamba, Manimala, Achenkovil, Meenachil and Moovattupuzha rivers drain into this lake. The other important backwaters are Veli, Kadhinamkulam, Anjingo, Edava, Nadayara, Paravoor, Ashtamudi, Kayamkulam, Kodungallur and Chetuva. The Sasthamcotta lake in Kollam district is a major fresh water lake in Kerala, it is situated in a picturesque setting with a high hills on three sides.
The deltas of the rivers interlink the back waters and provide excellent water transportation in the low lands of Kerala. The whole land is endowed with a panoramic beauty of landscape. The mid land and the coastal areas are densely populated and the main towns and cities are situated in the coastal regions. From North to South, there are many principal ports and towns like Kannur, Badagara, Quilandy, Kozhikode, Beypur, Ponnani, Kochi, Alappuzha, Kollam, Thiruvanatapuram, Kovalam and Vizhinjam.