Shoppers at a new Lidl store in Dublin will get a unique insight into the city's medieval past.

The remains of an 11th century house are clearly visible beneath a glass section of the floor of the store on Aungier Street in the city centre.

The sunken-floored structure was discovered during excavations of the site, close to Dublin Castle.

"It is a unique structure for Dublin," said Paul Duffy from IAC Archaeology.

"I am sure it functioned as many things. As a house or as an extra space for the family.

"It is a domestic structure so you would have to imagine that there would have been a suburb here of Hiberno-Norse Dubliners who were effectively the ancestors of the Vikings," he added.

The remains of an 11th century house can be seen beneath a glass section of the floor of the store

A similar glass panel, near the store's checkouts, showcases an 18th century 'pit trap' associated with the stage workings of the former Aungier Street Theatre.

"It was the device that was used when you wanted an actor to come up and down and appear as if by magic on the stage.

"So we were delighted that such a meaningful part of the theatre was found, recognised and is now presented to the public. I think it's really fantastic that Lidl is displaying it right in front of their tills," said Linzi Simpson, consultant archaeologist on the project.

Information panels and artwork interpreting the remains are also displayed throughout the new store.

The 11th century structure was built by the Hiberno-Norse inhabitants of Dublin who were ancestors of the Vikings (Image: Matthew Ryan)

"Lidl has over 10,000 stores throughout the world. But this is something very unique and it really makes archaeology accessible to the public," said Vincent Cronnolly from Lidl Ireland.

The foundations of the medieval parish church of Saint Peter, which served Dublin parishioners from c.1050 to c.1650, are also preserved beneath working areas of the new building.

"Hopefully this project sets a new benchmark for the treatment of archaeological heritage in the city. There has been a very collaborative approach from all sides.

"I think we have to challenge the Celtic Tiger approach of putting up a hoarding, excavating a site and then putting up a development," said Dublin City Archaeologist Dr Ruth Johnson.

Archaeologist Paul Duffy at work beneath the glass floor of the Aungier Street store

Reflecting on the unique glass display for the 11th century house, Paul Duffy said: "I'm waiting for the Dubliners to come up with a name for this thing.

"It's going to have its own Dublin nickname like the 'stiletto in the ghetto' for The Spire. But it's going to be part of city life and the story of Dublin."

Lidl says 24 people will be employed in the €3m store, which opens tomorrow.

The rest of the development comprises student accommodation.