What is a key type of Architecture in Somerset 
Somerset has 11,500 listed buildings, 523 scheduled monuments, 192 conservation areas, 41 parks and gardens including those at Barrington Court, Holnicote Estate, Prior Park Landscape Garden and Tintinhull Garden, 36 English Heritage sites and 19 National Trust sites, including Clevedon Court, Fyne Court, Montacute House and Tyntesfield as well as Stembridge Tower Mill, the last remaining thatched windmill in England. Other historic houses in the county which have remained in private ownership or used for other purposes include Halswell House and Marston Bigot. A key contribution of Somerset architecture is its medieval church towers. Jenkins writes, "These structures, with their buttresses, bell-opening tracery and crowns, rank with Nottinghamshire alabaster as England's finest contribution to medieval art."