Yarn Market, Dunster fire in the Civil War. Nearby was an older cross known as the Butter Cross which has subsequently been moved to the outskirts of the village. The Yarn Market is an octagonal building constructed around a central pier. The tiled roof provides shelter from the rain. Dunster Castle stands on a site which has been fortified since the late Anglo-Saxon period, signifying the importance of the area. After the Norman conquest of England in the 11th century, William de Mohun constructed a timber castle on the site as part of the pacification of Somerset. A stone shell keep was built
Dunster Avill, offering a natural defence and making the village an inland port. Nearby is the Dunster Park and Heathlands Site of Special Scientific Interest noted for nationally important lowland dry heath, dry lowland acid grassland, wood-pasture with veteran trees and ancient semi-natural oak woodland habitats. The fauna of the lowland heath includes the heath fritillary ("Mellicta athalia"), a nationally rare butterfly. The assemblage of beetles associated with the veteran trees is of national significance because of the variety and abundance of species. Along with the rest of South West England, Dunster has a temperate climate which is generally wetter and