The River Hen rises in an area of northwest Bristol known as Cribbs causeway. Originally a romantic story was circulated about Cribbs Causeway getting its name from Tom Cribb a bareknuckle fighter. However, this proved later to be untrue, as Cribbs causeway was so named long before Tom Cribb was born. More than likely the name derived from Crybs Croft a farm which existed in Henbury as early as 1280. Tom Cribb by the way, came from Hanham, a suburb clear across the other side of the city of Bristol.

Cribbs Causeway was in fact originally a road built by the Romans , linking Sea Mills (Portus Abonae) with Gloucester (Glevensium) to transport supplies to the garrison.

The Hen runs through culverts  down through Henbury and crosses Henbury road creating a ford close to the Salutation Arms public house. As it enters the Blaise castle estate its name changes to Hazel Brook. It flows into the River Trym at Coombe Dingle. Its total length is about 4.5 miles.

As a boy growing up in Henbury, the River Hen was a favorite place to explore. Groups of us  would tramp stream until our progress was blocked by a narrow culvert close the Henbury station. Sometimes we would build small dams to create larger pools of water or just poke about with an old jam jar in the hopes of finding newts or sticklebacks.

Hazel Brook flowed from the ford at Henbury road through one end of Henbury churchyard through Blaise Woods. Along the way, it passed through a natural rock formation called the Giant’s Soap dish (see Legendary Giants) to an area of Westbury-on-Trym known as Coombe Dingle. Here Hazel Brook flows into the River Trym.