From Shotesham the river flows northwards through Stoke Holy Cross, Dunston, Caistor St Edmund, Markshall and Arminghall.

[2] The Tas valley contains many interesting historical sites including: an Iron Age hill fort at Tasburgh, the old Roman settlement of Venta Icenorum (now Caistor St Edmund) and the site of a woodhenge at Arminghall.

The mill at Stoke Holy Cross was the first location of the Colman's mustard business.

In Roman times the River Tas was considerably larger and provided a major transport route for the inhabitants of Venta Icenorum.

One of the largest roach ever caught in the river was a 2.6 pound specimen landed by local angler Bill Coleman in 1972.