The discovery of artefacts at two excavation sites in 2010 revealed human settlement at Monmouth in the Mesolithic period. The artefacts uncovered by archaeologists at St James' Square and Wyebridge Street included charcoal, flints, and bone fragments. The discovery has led to the conclusion that the site of Monmouth, adjoining the confluence of the rivers Monnow and Wye in south east Wales, was inhabited thousands of years earlier than previously believed.
The earliest known settlement in Monmouth prior to the most recent find was about 2,500 years old. The excavations that took place in 2010 during the course of gas main replacement work at St James' Square and Wyebridge Street drew the attention of local archaeologists. The sites included the former riverbanks of the River Wye before its change in course. It initially ran along what is now St James' Street. Monmouth archaeologists, including Jane Bray and Stephen Clarke, had watched the excavation work closely and were intermittently evaluating the trenches. While monitoring the excavation process, Clarke, chairman of the Monmouth Archaeological Society, noticed a fleck of charcoal. It was in ancient sands, below thousands of years of Roman remains and river pebbles. The charcoal alerted the archaeologists to the possibility of additional significant findings.
The artefacts that the Monmouth archaeologists discovered were flint tools and bone fragments, in addition to charcoal. Archaeologist Clarke notified Elizabeth Walker, curator of Paleolithic and Mesolithic Archaeology at the National Museum Wales in Cardiff. She indicated that the flints were from the Mesolithic era. The curator initially estimated that they were about 6,500 to 7,500 years old. They included microliths, both flint arrow points and flint harpoon barbs that would have been attached to wood or antler. The microliths were used for fishing or hunting. Another artefact that was retrieved was a scraper that could have been used to clean animal skins or scrape bark and small branches. In addition to the stone tools, waste pieces of flint from the production of tools were found.