Tresillian River
The Tresillian River is a river in the middle of Cornwall which rises as a stream in the Clay Country in the midst of the county, and runs down to the south-west, where it opens into a broad, tidal creek to join that of the Truro River.
The creek is one of several tidal inlets, which bring the sea deep into the body of Cornwall, leading into the Carrick Roads.
The river begins by the clay workings which scar the landscape around St Austell, in this case somewhat to the north of that town. From here it comes south, the B3275 following its valley, passing through no villages of any size.
At Tresillian the river comes tidal, and soon expands, the little stream among mudflats becoming a broad channel at high tide. It enters the Truro River at Malpas.
Tresillian was once a seaport, the trade using the river, until the head of the creek silted up.