Bhagavan Sri Krishna, in the form of Chaitanya Mahaprabhu, came to Vrindavana to fulfill the purpose for which He descended to this material world. There is a direct connection between Mahaprabhu’s coming to the world in 1486, and His coming to Vrindavana on Kartika Purnima in 1515.

Other than sankirtana prachara, which Srila Krishnadasa Kaviraja said is the external purpose (bahya hetu Cc. 1.1.102) for His appearance, Krishna Chaitanya, assuming the mahabhava and prema kanti of Srimati Radharani, came for 3 principal reasons mentioned in Sri Chaitanya Caritamrta (1.1.6):

Sri radhayah pranaya mahima kidrsho vana yaiva
Svadyo yenadbhuta madhurima kidrsho va madiyah
Saukhyam casya mad anubhavatah kidrsham veti lobhat
Tad bhavadhyah samajani shaci garbha sindhau harinduh

“Bhagavan Sri Krishna appeared as Mahaprabhu to
1) understand the greatness of Radhikara prema;
2) taste the amazing sweetness of His own love;
3) experience the happiness Radha feels in loving Him.” 

Later Kaviraja Goswami confirms the main cause of Sri Krishna descent: 

Sei bhave nija vancha karila purana avatarera ei vancha mula karana 

“In the mood of Radha bhava (mahabhava), Mahaprabhu fulfilled His own desires. This is the root cause of Krishna’s avatara as Sri Chaitanya Mahaprabhu. (Cc. 1.4.221)

In 1515, Sri Chaitanyadeva came to Vrindavana and visited many places within Vraja Mandala. After Radha-Krishna closed Their Bhauma Vrindavana prakata-lila, Sri Radha Kunda became hidden and lost (tirtha lupta) to the world. Being the sarvajna bhavagan, however, the omniscient Mahaprabhu revealed the exact location of Radha’s Lake of Love Divine. 

After joyfully bathing in Radha Kunda, Krishna Chaitanya glorified it with prayers:

“Radha Kunda is very dear to Sri Krishna because it is very dear to Priyaji Sri Radha” (taiche Radha kunda priya priyara sarasi Cc. 2.18.7).
“Sri Krishna gives Radha prema to whoever bathes even once in Radha Kunda” (sei kunde yei eka bara kare snana, tanre Radha sama prema Krishna kare dana Cc. 2.18.10) 

Thus the merciful and compassionate Sri Chaitanya Mahaprabhu fulfilled His purpose in coming to Vrindavana. 

When the brothers Sri Rupa and Sanatana Goswamis met Mahaprabhu in Ramakeli, they glorified the Lord, saying:

namo maha vadanyaya Krishna prema pradaya te
Krishnaya Krishna Chaitanya namne gaura tvishe namah

“You are Krishna Himself appearing as Sri Krishna Chaitanya with the golden color of Srimati Radharani. You are most charitable for You are giving Krishna prema. We offer our respectful obeisances unto You.” (Cc. 2.19.53) 

In 1515, Mahaprabhu bestowed the greatest charity upon the world by coming to Vrindavana to reveal the lost reservoir (lupta tirtha) of Radha prema. Combining the affection of bhakta-vatsalya Sri Krishna and the unlimited compassion of Karunamayi Radha, Chaitanya Mahaprabhu came to Vrindavana to reveal Radha Kunda and make Radha prema available to everyone in the world for time ever more. 

Sri Chaitanya Mahaprabhu’s Vrindavana Agaman Lila ki jai!
Jai Jai Sri Radhe! 

By Mahanidhi Swami