Pontcysyllte Aqueduct & Trevor Basin Visitor Centre

This breathtaking structure is over 200 years old and still carries the Llangollen Canal over the River Dee Valley. It offers visitors the experience of crossing the world’s longest and highest navigable aqueduct. Both it and the canal are of great historical and engineering importance.

The site is managed by the Canal and River Trust, which has a management plan to guide conservation efforts and continuously works to maintain the integrity of the hydraulic and civil-engineering structures.

The name “Pontcysyllte” comes from the Welsh language and means “Cysyllte Bridge” or “Bridge of Cysyllte.” Cysyllte was a township in the old parish of Llangollen, where the bridge’s southern end is located. This name shows how closely connected the aqueduct is to the local community.

About the Aqueduct

Take a Walk Other the Aqueduct

Design and Construction

The Pontcysyllte Aqueduct and Llangollen Canal (originally called the Ellesmere Canal) were built during the late 18th to early 19th century. They used civil engineering techniques that had never been tried before. It is a remarkable engineering feat that uses metal arches supported by tall, slender masonry piers.

The aqueduct has four supporting arches per span, each made of cast-iron ribs. The external arches are cast with an un-pierced web to provide greater strength but at the cost of extra weight. This use of cast iron is similar to that of the stone arch it replaces, utilising the material’s strength in compression.

The canal trough is formed by laying transverse cast plates. The cast iron trough is not fixed to the arches, but lugs are cast into the plates to fit over the rib arches to prevent movement. It was left with water inside for six months to ensure the aqueduct was watertight.

Unlike a road or railway viaduct, the aqueduct experiences virtually constant vertical loading stresses. This is because of Archimedes’ principle. When a canal boat crosses the aqueduct, an amount of water equal to the weight of the boat is displaced into the canal at either side.

The towpath is above the water, with cast-iron pillars supporting the inner edge in the trough. This arrangement allows water displaced by a boat to flow easily around the boat under the towpath.

Railings on the outside edge of the towpath protect pedestrians and horses once used for towing from falling from the aqueduct. However, the holes in the top flange of the other side of the trough, which were originally included so that railings could be fitted, were never used. Added to that, the trough sides rise only about 15 centimetres above the water level, less than the depth of the freeboard of an empty narrow boat. This gives the helmsman the impression of being at the edge of an abyss!

It took ten years to design and build by civil engineers Thomas Telford (the first President of the Institution of Civil Engineers) and William Jessop. It opened in 1805 and is made from local stone. There are 18 arches, with the 19th arch featuring a locked plug that is removed every four years for maintenance.

Both the Aqueduct and Llangollen Canal are examples of the innovations brought about by the Industrial Revolution in Britain. The canal’s construction in a challenging geographical area meant technical advancements in engineering were needed.

They made significant contributions to the development of heavy cargo transport and overall progress during that era.

The Decline and Rebirth

The amount of commercial traffic on the canal decreased significantly after a waterway breach occurred near Newtown, Powys, in 1936. As a result, boat movements across the aqueduct to Llangollen stopped by 1939.

The Llangollen Canal was finally closed to navigation in 1944 as it had also breached its banks east of Llangollen near Sun Bank Halt. This caused a goods train of 16 carriages and two vans to crash into the breach, killing one and injuring two engine crew.

However, the aqueduct was still required as it fed for the remainder of the Shropshire Union Canal and for supplying drinking water to a reservoir at Hurleston, so it was saved from closure. In 1955 the future of the canal and aqueduct was secured when the Water Board agreed to maintain the canal.

Since then, leisure boating traffic on the canal has increased, and it has become a popular destination for holidaymakers in Britain. The Aqueduct is now managed by the Canal & River Trust, and otters have been spotted in the area.

A view from below

A UNESCO World Heritage Site

UNESCO recognises the Pontcysyllte Aqueduct Wales and Llangollen Canal as exceptional and of universal value. The site has World Heritage Status. The innovation shown here has inspired numerous other projects worldwide, leading to advancements in transport, inland waterways, civil engineering, land-use planning, and the application of iron in structural design.

It is also grade 1 listed.

Visiting the Aqueduct

Exploring the Visitor Centre

Start your aqueduct adventure at the Trevor Basin Visitor Centre. It is completely free and provides interactive models, informative videos, and souvenirs. It is open most days from 10:00 to 16:00, and it’s the ideal place to begin your exploration of the Aqueduct and the nearby sights.

There are public toilets at the visitor centre.

Boat Trips & Boat Hire

Get ready to feel the excitement of crossing the aqueduct either on foot or, better still, by boat while enjoying the stunning views of the River Dee Valley below.

Two companies operate boat trips, Anglo-Welsh and Llangollen Wharf, and provide boat tours across the Pontcysyllte Aqueduct that guarantee an unforgettable experience for tourists. If you’d prefer a self-drive day-hire boat, then companies can be found on our Day Hire listings.

Or why not consider a weekend, midweek, week or longer break with one of the independent and family-owned boat hire firms – and cruise the whole of the Llangollen Canal.

Pontcysyllte Aqueduct Walk

How about a Pontcysyllte Aqueduct Walk? Although there are a lot of steps, the climb down to the valley floor is more than worth it, as it offers a spectacular view of the crossing.

But it’s not just the aqueduct itself that makes these walks so special. The surrounding landscape is a sight to behold, with rolling hills, lush greenery, and the meandering canal. More accessible walks are possible, and you can venture slightly further afield along the Canal towpath in either direction.

Being a towpath, it is virtually flat. However, you can still get spectacular views of the valley. Venturing west for a couple of hours easy stroll will take you to the beautiful riverside town of Llangollen with its interesting shops and preserved steam railway.

Heading for an hour or two in the other direction will take you to Chirk, with its own stunning aqueduct and a tunnel that you can walk through if you dare!

Other Things to Do in the Area

When visiting the Pontcysyllte Aqueduct, several exciting activities and attractions are worth exploring nearby.

One of the top attractions in the area is Chirk Castle, located just a short distance from the aqueduct. Chirk Castle is a magnificent medieval fortress that dates back to the 13th century. Visitors can take a guided tour of the castle and explore its stunning gardens and grounds.

The Llangollen Railway is a heritage railway that runs for 10 miles between Llangollen and Carrog, passing through picturesque countryside along the way. This scenic journey offers a unique opportunity to experience the charm of steam travel and enjoy stunning views of the River Dee and the Dee Valley.

The railway also hosts special events throughout the year, such as themed train rides and dining experiences, making it an ideal activity for both families and railway enthusiasts.

Read More

You can read more about bridges and aqueducts and the engineers who built them.