Iraq Banner Desktop

Store Banner Mobile

Subterranean Discovery: Medieval Welsh Abbey Tunnel from Norman Invasion Period

Subterranean Discovery: Medieval Welsh Abbey Tunnel from Norman Invasion Period


Archaeologists announced the discovery of a 12th-century tunnel network beneath an abbey in Wales. This tunnel beneath a popular Welsh abbey is so long that that archaeologists project that it will take many years for them to get to the end of this now emerging medieval subterranean find. 

The Norman invasion of Wales opened the church in Wales to new monastic orders. Thirteen Cistercian monasteries were founded in Wales between 1131 and 1226 AD and the first was situated near Tintern, Monmouthshire, close to the border with England. Tintern Abbey, a vast gothic structure, which fell into ruin in the 17th century, attracts around 70,000 visitors a year.

A team of water engineers working for Western Power Distribution unearthed the tunnel network in 2021, while moving an electricity pole. A spokesperson for Western Power Distribution told the Daily Mail that “the four-foot [1.2 meter] high tunnels” weren’t marked on any previous ordnance survey maps and their discovery was completely unexpected. Works at the site were put on hold so that archaeologists could assess the condition of the tunnels.

A section of the 4-foot (1.2 meter) high Welsh abbey tunnel recently discovered beneath Tintern Abbey, Wales. (Western Power Distribution)

The Medieval Welsh Abbey Tunnel Find Is Amazing!

Team leader Allyn Gore said his crew of excavators were working in a trench located “on a customer's property” when they stumbled across the first evidence of the ancient Welsh abbey tunnel network. Soon after the excavation works began, the digging team discovered what they initially thought to be a cave. Fearing dig safety issues, they stopped excavating immediately.

Mr Gore said he has been involved in other excavations where “old wells and cellars not shown on any plans were discovered,” but he admitted that he has never been involved with anything as “exciting and impressive as this,” according to the Daily Mail.

An article in the Welsh Republic World says the excavation works were “stopped immediately” when the tunnel was reported. Site manager Bradley Griffiths contacted the Welsh government’s historic and cultural heritage service (Cawd), who sent a representative to the site.

At this point, it is thought that the Welsh abbey tunnel network might be associated with a nearby medieval iron works that often required reservoir complexes known as “Carron Dams.”

Another section of the Welsh abbey tunnel found under Tintern Abbey, Wales. (Western Power Distribution)

2021: Year Of Medieval European Tunnel Discoveries

The announcement of the discovery of ancient Welsh abbey tunnels came only two days after Ancient Origins wrote about a similar discovery in Poland.

According to The First News, archaeologists in Poland discovered “a secret tunnel underneath Ducal Castle in Szczecin, Poland, while exploring Nazi-era passages built during WWII.” According to the director of Ducal Castle, Barbara Igielska, the brick-and-mortar materials used to make this ancient tunnel were radio carbon dated to the medieval period.

Karol Krempa, head of the castle's renovation and investment department, said further work was vital in the understanding and safeguarding of the castle, but they can’t rule out that there might be “much more to the 270-meter section of tunnel than we are currently aware of.” This brick tunnel section serves as a groundwater runoff channel and initial inspections suggest the tunnel in Wales runs parallel to the Angiddy Brook flowing through the Wye Valley.

This observation suggests the Welsh abbey tunnels might have also served a “hydrological function” similar to the Ducal Castle tunnel in Poland. Tunnels are notoriously dangerous discoveries for after being excavated they can threaten to undermine the stability of the surrounding architecture. 

While excavators in Poland are suggesting they back fill the tunnel, Barbara Igielska at Ducal Castle wants to “maintain and restore it for tourists to experience.”

Regarding the Welsh abbey tunnel discovery, it looks to be a very complicated project. A strategy is currently being drafted and the excavators will soon set about a complete exploration of the tunnels, but Mr Gore says no matter how fast they progress it will likely take many years to complete the excavation.

Top image: Tintern Abbey, founded on May 9, 1131, is the location of the recently discovered Welsh abbey tunnels.                     Source: Saffron Blaze / CC BY-SA 3.0

By Ashley Cowie

ashley cowie's picture


Ashley is a Scottish historian, author, and documentary filmmaker presenting original perspectives on historical problems in accessible and exciting ways.

He was raised in Wick, a small fishing village in the county of Caithness on the north east coast of... Read More

Next article