Buddhist Dictionary of Pali Proper Names by G P Malalasekera
Nāgalena
Nāgalena：A cave in Kotlpabbata vihāra．A novice once recited there the Mahāsamaya Sutta，and a goddess，in the nāga tree outside，applauded him．She had been present when the Buddha preached the sutta when，she said，the concourse of devas was so great that she could get a foothold only in the sea near Mahagāma in Ceylon； yet she could see and hear the Buddha distinctly．DA．ii．895．