The boat cruise on Periyar Lake, in the cardamom hills at Thekkady, is one of Kerala’s classic experiences — a glide across still water past elephants and gaur on the shore. What most visitors don’t realise is that the lake itself is barely a century old, and entirely man-made.
A Victorian dam and a new lake
The reservoir was created in 1895 by the Mullaperiyar Dam, built across the west-flowing Periyar River during the British colonial period under the engineer John Pennycuick. Its purpose was not scenery but water: the dam diverts the Periyar eastward, through the mountains, to irrigate the dry plains of Tamil Nadu around Madurai. In flooding the valley behind the dam, it drowned the forest and left the sinuous lake that now sits at the centre of the reserve.
The ghost trees
Look across the water on the cruise and you will see bare, silvered tree trunks rising from the surface — the skeletons of the forest that stood here before 1895, preserved by the water. They give the lake its haunting, half-drowned beauty, and are a quiet reminder that this tranquil scene was once dry, living woodland.
From hunting ground to tiger reserve
The forest around the new lake was declared a reserve as early as 1899. In 1978 it was brought under India’s Project Tiger and became the Periyar Tiger Reserve — today one of the country’s best-known reserves, spread across the Idukki hills. Tigers are elusive here; what you are far more likely to see are elephants, gaur, sambar and birdlife gathering at the water, especially in the drier months.
- The Periyar Lake boat cruise is the classic way in; book early, as slots fill fast in season (roughly October to February).
- Guided nature walks, bamboo rafting and the Tiger Trail trek offer quieter, closer wildlife experiences than the boat.
- Tiger sightings are rare — come for the landscape, the elephants and the spice-hill setting rather than a guaranteed big cat.
Frequently asked questions
Is Periyar Lake natural or man-made?
Periyar Lake is man-made. It was formed in 1895 when the Mullaperiyar Dam was built across the Periyar River during the British period, flooding the valley behind it to create the reservoir at the heart of Thekkady.
Why are there dead trees in Periyar Lake?
The bare tree trunks rising from the water are the remains of the forest that stood in the valley before it was flooded by the dam in 1895. Preserved by the water, they give the lake its distinctive, half-drowned look.
Will I see tigers at Periyar Tiger Reserve?
Tiger sightings are rare. Periyar is better known for elephants, gaur, sambar deer and birds gathering near the lake, along with its beautiful cardamom-hill setting. The dry season, roughly October to February, is the best time for wildlife.