Causeway House NY7666 : Heather-thatched Causeway HouseNY7666 : Causeway HouseNY7666 : Causeway House This property has been a Landmark Trust 'let' for over 20 years. According to their 2011 handbook, this is the only house in Northumberland still thatched with heather, although one bedroom, open to the thatched roof, is not recommended for Winter use!