He [Bhaktisiddhanta] entered into prātaḥ-kālīna-līlā. Early in the morning, he entered into the nitya-līlā, this prātaḥ-kālīna-līlā. He entered into that līlā on the 1st  of January 1937 at 5:30 A.M. at Calcutta, Bagbazar Gaudiya Math. He disappeared there. He did not go to Vrindavan for disappearance. That is Vrindavan -  where there is such a sādhu, that is Vrindavan. 

Then his transcendental body was taken to Mayapur, at the birthplace of Mahaprabhu known as Yogapitha. There you will find his samādhi-mandira.