St Austell River

The highest natural point of the moorland is Hensbarrow Beacon at 312 metres (1,024 ft); however modern china clay mining waste tips now rise above it.

The river has two main tributaries, the first of which begins several hundred metres south of Hensbarrow Beacon at grid reference SW 991 550 and heads south-east past the southern edge of Gunheath china clay pit.

The second tributary begins within the massive Littlejohn's/Dorothy china clay pit in a region that was originally known as Longstone Moor, where previously it had been a long, shallow valley that had drained the surrounding high moorland area.

From there, it winds roughly south until it too reaches another viaduct belonging to the Cornish Main Line railway, wherefrom it turns east-southeast and follows this heading for approximately a kilometre into St Austell, where it joins the Trenance Valley river.

The final section of the river can vary course significantly as it crosses Pentewan beach and flows into the sea at grid reference SX 020 470.