The Monmouthshire and Brecon Canal

Our scenic canal celebrated its 200th anniversary in 2012. This peaceful waterway was built as an industrial corridor for lime, limestone, timber, coal and iron. In its 19th century heyday, it was supported by horse-drawn tramroads that were used to bring raw materials from the hillsides.
The section of the Mon and Brec which runs through the Brecon Beacons National Park was originally called the Brecknock and Abergavenny Canal. Mainly supplied with water by the River Usk, it stretched for 35 miles from Brecon to Pontymoile, near Pontypool. Construction began in 1795 and the final section was completed in 1812.

The Brecknock and Abergavenny Canal was built 30 feet wide and four feet deep, with 100 bridges, a tunnel and six locks. It followed the contours of the hills as closely as possible to minimise the number of locks. This made it relatively long, but saved on construction costs and made the canal quick to navigate. The longest lock-free stretch was 23 miles from Llangynidr to Pontymoile – impressive, given the hilliness of the terrain.

At Brynich, just below Brecon, an ambitious four-arch aqueduct was built to carry the canal over the River Usk. There's another grand stone aqueduct at Gilwern, which has only a single arch but is very high. It takes the canal over the River Clydach.

The 343m long Ashford Tunnel in the stretch between Talybont and Llangynidr was only wide enough for a single canal boat, with no towpath. In the days before engines, the horse would be led over the hill while the boat was poled through the tunnel, or legged, by men lying on their backs and pushing against the walls with their feet.

A vital local network

Connected to the canal were tramroads with iron rails which allowed horse-drawn wagons to bring heavy loads from the nearby quarries and mines to the canal banks. There was a tramroad from the coal mines in the Clydach Valley to Gilwern. The Brinore Tramroad linked the limestone quarries at Trevil near Tredagar to Talybont-on-Usk.

The busiest era for the canal was the early 19th century. At over £200,000, it had been colossally expensive to build but the investment seemed worthwhile as it was far cheaper and more efficient to carry cargo by water rather than by road. By 1810, the canal was carrying 150,000 tons of coal each year, on heavily-laden barges towed by horses.

Lime, used chiefly as a fertiliser to enrich the fields, was another important cargo. Limestone was dug out from the nearest quarries and taken by tramroad or cart to limekilns which were specially built close to the canal banks. Remains of these kilns can still be seen today.

Decline and restoration

The arrival of the steam railways later in the 19th century caused a steep decline in the fortunes of the canals. In 1880 the Brecknock and Abergavenny Canal was taken over by the Great Western Railway and by the early 20th century, commercial carrying had all but ceased.

Throughout the 20th century, various parts of the waterways were filled in for road construction. Eventually, vigorous campaigning by canal enthusiasts heralded a new dawn for the canal, and in 1968, restoration work from Brecon to Pontymoile began in earnest. Much has been achieved and almost all the original Brecknock and Abergavenny Canal is now navigable. The only bit missing is a short stretch at the top, beyond Brecon Basin.

The towpath of the Monmouthshire and Brecon Canal has good views over farmland, woodland and mountains. The canal is also home to a wide range of flora and fauna. Click here to find out more about this appealing environment.

Visiting the Monmouthshire and Brecon Canal

The waterway and its towpaths are open to the public. Access for walkers is free, while boating and canoeing requires a licence. Click here to find out more.

How to get there

The canal runs parallel to the A40 between Brecon and Abergavenny and the A449 between Abergavenny and Pontypool.

Nearest towns and villages

Brecon, Abergavenny and the canalside villages

OS maps

Explorer Maps OL12 or Landranger Maps 160