Horsted Keynes KAYNZ is a village and civil parish in the Mid Sussex District of West Sussex, England. The village is about 5 miles (8 km) north east of Haywards Heath, in the Weald. The civil parish is largely rural, covering 1,581 hectares. At the 2011 census, it had a population of 1,586, increased from 1,507 in 2001. The 0° meridian passes about 1 mile to the east of the village of Horsted Keynes.