In Padma Purāṇa, Kārtika Māhātmya, it is stated that Radha Kund is very dear to Shri Hari and is situated near Giri Govardhan hill. By taking bath in Radha Kund on the eight day of waning moon in the month of Kārtika[Bahulāṣṭamī] one can greatly please Lord Hari who enjoys his pastimes there. This kunda is as dear to Śrī Krishna as Radha Herself.
As a result of the killing of the Arishtasur demon, a lila of mutual purification followed with the appearance of Shyama Kund from Krishna’s kick, and most importantly Radha Kund from Radha/gopi’s dig, an invitation to all celestial rivers and then a bath; now this has become an annual midnight celebration.
All glories to this Bahulāṣṭamī day, the appearance of Śrī Radha Kund!
After bathing in Radha Kund, Krishna declared that henceforth, anyone who with firm faith took their bath on this day would achieve the same ecstatic love that Radharani had for Him. Radharani and Her girlfriends then took bath in Shyama Kund and Radhika declared that anyone who takes bath in Shyama Kund, will achieve the same ecstatic love that Krishna has for her.
This pastime occurred at 11:45 p.m. on the eighth day of the waning moon in the auspicious month of kartika. Last night thousands delighted in the dīpa-dāna and midnight bathing. A beautiful floating deity of Radharani presided, decorated in changing colored lights. A full arati with triple level dīpa lamps was performed from the steps by five pujaris amidst the resounding chanting of Radha’s name.
As an offering on behalf of Srila Prabhupada, ISKCON Radha Kund was allowed to sponsor the dīpa-dāna with assistance from devotees from all around the world: Braja, India, USA, UK, Poland, Ukraine, and Spain — a unity in diversity. These devotees cleaned up both kundas of cloth, flower debris and melons, well into the early morning.
This was a festival of glorification, to appreciate, honor and facilitate, but most importantly an effort to preserve, protect and care for the Dham.