These two kunds are considered as the holiest places as both Radha and Krishna have performed their transcendental pastimes on the banks of these Kunds. It’s believed that both Radha Kund and Shyam Kund were the confidential bathing places of Radha and Krishna. They used to meet on the bank of Radha Kund and also performed the celebrated pastime of Rasalila here at this Kund. Radha Kund is considered as the transcendental liquid form of Sri Radha and Shyam Kund as the transcendental Liquid form of Lord Krishna. Thus both of these are most revered among the Gaudiya Vaishnavas. About 4800 years ago, king Vajranabh excavated both Radha Kund and Shyam Kund and built Ghats on their banks. But, during the course of time both these lakes disappeared. With the advent of Bhakti movement in 16th century Sri Chaitanya Mahaprabhu along with his disciples during his visit to Vrindavan, excavated these kunds. In the anticipation of the attack by the tyrant ruler Aurangzeb on Vrindavan, all the important deities of the temples of Vrindavan were secretly hidden in the Radha Kund for many days. Later they were moved to Kamyavan from Radha Kund and then to Jaipur in Rajasthan for safekeeping.
According to the legendary story, Kansa the tyrant ruler of Mathura sent one of his loyal servants named Arishtasura, to kill Krishna. The demon had the form of a fierce bull. Soon on reaching Vrindavan, Arishtasura started searching for Krishna. He caused a wave of terror among the people of Braj. When Krishna came to know about the terror of the furious bull around the Govardhan hill, he soon reached the place and fearlessly challenged the bull for a fight. Arishtasura got infuriated at the challenge of such a small boy and thus, in a fit of anger he attacked at Krishna with a huge force. As the bull approached closer to him, Krishna caught him by his horns and after whirling threw him far away. The demon fell on ground with a loud bump and soon lost his senses and died. Watching this heroic deed of Krishna, all the Gopas congratulate him. But Gopis and Sri Radharani refused to talk to him saying that he has committed a great sin of slaying a bull who is the member of cow family. They advised Krishna to go and take bath in all the tirthas of world to wash out his sin and then only they will associate with Krishna. Krishna tried to explain to gopis that Arishtasura was a demon but gopis refused to listen to him. Thus for the pleasure of Radharani and other gopis, Krishna dug the ground with thump of his heel and then meditated upon all the holy tirthas and ordered them to fill the pit with their sacred waters. Soon, with the consent of Krishna the Kund was overflowing with the sacred waters of the tirthas. This Kund came to be known as Shyam Kund.
Krishna took bath in Shyam Kund and purified his body of the sin of killing a bull. Then, to tease gopis he started boasting about the glory Shyam Kund. Not to be outdone by Krishna, Radharani suddenly broke her bangle and along with other gopis started digging the ground near to Shyam Kund. After digging up the Kund they brought the water in earthen pots from the Manasi Ganga to fill that Kund. Viewing this generosity of Radharani, all the tirthas appeared before her and requested her to provide them with an opportunity to fill her new Kund with their sacred waters. Radharani agreed to their request and soon the water from all the tirthas broke through the bank of Krishna Kund to fill the newly dug Radha Kund. As it was dug by Radharani thus it came to be known as Radha Kund. It’s a belief that one who takes bath in both these Kunds with complete devotion and faith will achieve the great love of Lord Krishna and Radha.