The Lakshmana Tirtha (Lakshmantīrtha River) is a river of Karnataka, India. It rises in Kodagu district and flows eastward. It joins the Kaveri in the Krishna Raja Sagara lake.
Mythological origin of Lakshmana Tirtha 
One day when Rama with his followers was living in Irpu, his younger brother Lakshmana, in a fit of madness, insulted him by returning the bow and arrows which he had received from Rama. But soon repenting of his rashness, Lakshmana asked forgiveness, offering at the same time to throw himself into a large fire as an atonement for his crime. He accordingly shot an arrow against the foot of the rocks at Irpu, when a large fire flared up, into which he threw himself. In order to save his brother, Rama immediately created a river to put out the fire, but it was too late. Rama afterwards desired to consecrate the spot, and ordered the dwarf Hanuman to bring a linga from Kashi (Varanasi) within an hour and a half. During his absence, Rama, fearing that Hanuman would not be back in time, made a linga himself of river-sand, in which operation he was surprised by Hanuman, who flew into a rage for having troubled himself in vain. He twisted his enormous tail round one of the neighbouring hills, Hanuman betta, and attempted to upset it. Rama, to comfort the furious Hanuman, assured him that Hanuman's linga should become even as more famous than his own. So the new linga was set up at Herumalu, and the festive day of its worship precedes that of the linga at Irpu. Thus the river is called Lakshmanathirtha.
Coordinates: 12°24′57″N 076°26′34″E / 12.41583°N 76.44278°E