A team from Museum of London Archaeology has uncovered the largest mosaic floor thought to have been found in the UK capital for 50 years.

A section of the mosaic was uncovered during pre-construction works near London Bridge in southeast London, near the Shard – London’s most modern building.

The excavations precede a regeneration project called Liberty of Southwark, which will build shops, homes and restaurants on the site.

The find comprises two areas of mosaic floor, featuring slate blue, white and red tessellated patterns. The area may have been a dining room – known as a triclinium – say the archaeologists on site.

The images depicted on the mosaics appear to be unique to London – as well as geometric patterns, the panels feature flowers, diamond shapes and rope borders.

Site supervisor for Mola, Antonietta Lerz, said:

“This is a once-in-a-lifetime find in London. It has been a privilege to work on such a large site where the Roman archaeology is largely undisturbed by later activity – when the first flashes of colour started to emerge through the soil, everyone on site was very excited.”

Dr David Neal – a former archaeologist with English Heritage and a leading expert in Roman mosaics – added that the mosaic appeared to be the work of a group of Roman mosaicists called the Acanthus Group, who developed their own style for London mosaics.

It is thought the mosaic dates to the 2nd/early 3rd century, with evidence of an earlier mosaic beneath it and alterations to the room over a period of time.

Archaeologists also think the room might have been part of a Roman guest house, known as a mansio – where important officials visiting London might have stayed.

All images Andy Chopping for Mola