Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Ancient City of Polonnaruwa' has mentioned 'River' in the following places:
Occurrence Sentence Text Source
Starting from Mahanagakula on the south of the Walawe river, Vijayabahu dispatched three armies to attack Polonnaruwa from three fronts.
The greatest of these systems is the Parakrama Samudra or the Sea of Parakrama which were also used as a large sea going ship anchorage via Mahaweli River.