Rettai Eri, locally known as Retteri, is a lake in the Kolathur area of Chennai, India which is visible from the 100 ft road.

Among them are the common tailorbird, the purple-rumped sunbird and the Asian openbill stork, a migratory bird.

The Water Resources Department (WRD) has decided to improve Rettai Eri along with waterbodies in Ambattur and Korattur at a cost of 850 million Indian rupees.

The improvement works include removing vegetation, desilting, introducing boating, and developing a park along the 3-km bund.

Other works include planting various species of medicinal and flowering saplings to attract butterflies and birds, creating a walkers' path and a mud flat in the middle of the lake.