The octagonal market building in the middle of Dunster's high street dates from around 1609 and is one of only two surviving yarn markets in England. It was built at the height of Dunster's wool and cloth trade, when the town was a significant manufacturing centre producing a cloth known as "Dunster" that was sold across southern England. The trade collapsed in the 18th century, but the market building survives in good condition.
English Heritage maintains the structure. It stands open to the street on all sides, with a conical stone-tiled roof supported on eight oak posts. The octagonal shape allowed merchants to display goods from multiple sides simultaneously. It is modest in scale but architecturally distinctive — the kind of structure that makes you realise how different English market towns once were from each other.