Sin: අවිස්සාවේල්ල avissāvēlla – Tam:அவிசாவள avisāvaḷai
‘Impassable Shore’ [Sitawaka/Seethawaka(pura)] – Town, WP, Sri Lanka
From Sin: avis(h)aya, ‘impossible’, ‘difficult’, ‘treacherous’; and wella/vælla, ‘shore’, ‘(sand)bank’, ‘sandy place’
Avissawella was the capital of the Sitawaka Kingdom (1521-93), a successor state to the Kingdom of Kotte which held off the Portuguese for most of the 16thC and was where the Dutch were almost wiped out following a failed attempt to capture Kandy.
Avissawella straddles the Sitawaka Ganga, a tributary of the Kelani, on a sharp bend. The river is impassable at this point featuring rapids interspersed with boulders. It is a popular site (along with Kitugala further east) for whitewater rafting
In the Hindu Ramayana epic, the demon Ravana abducts Sita and carries her off to Sri Lanka. Local legend says Sitawaka (‘Sita’s Circle‘, ‘Sita’s Bend’) is the site of the grove where he imprisoned her.

Whitewater Rafting in Sri Lanka Amila Tennakoon