Bhagwan Bahal (Vikramashila Mahavihar)

Bhagwan Bahal, formally Vikramashila Mahavihar and known locally as Thambahi, is held to be among the oldest Buddhist monasteries in the Kathmandu Valley — 'the eldest bihar,' by local reckoning. The neighbourhood grew up around it, and its name is the root of Thamel itself: Thamagram in Lichhavi times became Thabahil, and then Thamel. Thousands of travellers now pass its gate every day without knowing one of the valley's most storied Buddhist sites stands a few steps off the tourist street.

At its heart is not a conventional Buddha image but Singha Sartha Bahu (Singha Sartha Aju), a merchant hero worshipped as an incarnation of Karunamaya-Avalokiteshvara. His legend is famous: leading a trading caravan into Tibet, his men were lured by beautiful women who were in truth flesh-eating demonesses — given away by their backward-turned feet. Karunamaya appeared to him in the flame of an oil lamp, warned him, and carried the survivors home as a flying horse; those who looked back were snatched away, and Singha Sartha alone came through to found the monastery. His roughly seven-foot gold image, restored in 1996, is carried through the city in procession. Unusually among the valley's bahals, the monastery is looked after by the Pradhan clan rather than a Bajracharya–Shakya sangha.

The bahal was long a waystation for monks travelling between India and Tibet; the great Bengali master Atisha (Dipankara Shrijnana of Nalanda) is said to have stopped here in 1041 on his way to Tibet and to have had a hand in rebuilding it. Among its treasures is a celebrated Prajnaparamita manuscript dated to 1223, originally in five volumes of which four survive, penned in Ranjana script in gold ink on dark, insect-resistant paper — and still handled only with mask and gloves.