If you go by the ISKCON, Sridham Mayapur was created by Sri Radha. Here are the references (1, 2) from ISKCON. In favour of their claim, they have cited a text known as Ananta Samhita. However, the interesting part is this text itself is of very very recent origin according to Wikipedia. (I know Wikipedia is not an authentic source. I would be grateful if someone can shed some light on this text). I have a couple of questions.
First, During the time of Krishna (around 3000 BC), Bengal was outside Aryavarta. Krishna was getting raised in Vrindavana. Now, Sri Radhika from Vrindavana created a place for Krishna outside Aryavarta! This is confusing. As Krishna never stayed in Bengal, what is the point of creating a place for him in Bengal? I am even ignoring the fact that no ancient biographies of Krishna (like Harivamsha, Mahabharata) and even Srimad Bhagavatam never mentioned Radha.
Second, If the Mayapur Dhama was such an important place, why did biographers of Lord Chaitanya not mention such an important incident (that Sri Radhika created a place for Lord Krishna in Bengal)?