Theerthakkara is an important sacred site near the Thiruvumplavil Mahadeva Temple. According to legends, Lord Shiva and Goddess Parvati revealed themselves to grace a devotee at this place, who had taken care of a diseased cow on his way to Kashi. Seeing his sincere and dedicated attention, Lord Shiva and Goddess Parvati blessed him and asked him to perform his rituals in the water flowing through the hoof mark made by the cow. The devotee was assured that the water was the sacred Kashi theertham, the divine water from Kashi, and any ritual he performed there was as good as doing the same at Kashi. He also came to know that it was goddess Parvati who had come in the form of the cow to test his devotion.