A locality in the old Mahānāga garden, on the banks of the Mahāvāḷukagaṅgā. It was there that the Buddha hovered in the air on his first visit to Sri Lanka, in order to frighten the yakkhas. Later, Mahāsumana built there a shrine seven cubits in diameter, all of sapphire, and containing the hair given to him by the Buddha. After the Buddha’s death, Sarabhū, a disciple of Sāriputta, brought there the collar bone of the Buddha, which he deposited in the thūpa, increasing the height of the thūpa to twelve cubits. Uddhacūlābhaya raised it to thirty cubits, while Duṭṭhagāmaṇī, dwelling there during his campaign against the Damiḷa Chatta, increased it to eighty cubits (Mhv.i.24, 33 ﬀ; xxv.7; Cv. Trs.i.154, n.3). Vohārika Tissa erected a parasol over the thūpa (Mhv.xxxvi.34). Attached to the thūpa was a vihāra, near which lived the three Lambakaṇṇā: Saṅghatissa, Saṅghabodhi, and Goṭhābhaya (Mhv.xxxvi.58).
In later times, Sena II gave maintenance villages to the vihāra (Cv.li.74), as did also Kassapa IV (Cv.lii.14). Vijayabāhu I found the vihāra in a bad state of decay and had it restored, (Cv.lx.59) while Parakkamabāhu VI carried out repairs to the thūpa (Cv.xci.29). King Vīravikamma went from his capital to Mahiyaṅgana, a distance of one and three quarter leagues (seven gavuṭas) on foot, and held a great festival in honour of the thūpa (Cv.xcii.17). King Narindasīha is mentioned as having visited Mahiyaṅgana three times — once alone and twice with his army — and as having held magnificent festivals in its honour (Cv.xcvii.27 ﬀ). Vijayarājasīha held a festival there (Cv.xcviii.85), as did Kittisirirājasīha, who made a pilgrimage to the spot (Cv.xcix.38); he also made arrangements for travellers from Thailand to Sri Lanka to visit the spot and hold celebrations there (Cv.c.125 ﬀ). Rājasīha II was born in Mahiyaṅgana, while his parents were staying there for protection from their enemies. Cv.xcv.12.