The river is downstream from the Dolgoch Falls which is a popular nature site, and is followed for much of its course by the Talyllyn Railway.

Due to consonant mutation, Mathew becomes Fathew following the feminine noun afon ('river').

Likewise, the feminine noun pont ('bridge') gives rise to the name of the hamlet Pontfathew, now considered to be a part of the village of Bryn-crug.

The form River Fathew is also quite common, although it is difficult to justify on a linguistic basis as there is no consonant mutation in English.

The River Dysynni was thus forced to adopt a new course, and pushed its way through the hills northwestwards to find a new channel in the parallel valley to the north.