Considerable improvements were made to the fabric of all the buildings, not least the 12th-century keep. During this period, the castle was the headquarters and training centre of FIH PLC and for those running the conservation centre. Documentary and movie director Susannah White featured Denis Vernon and Appleby Castle in her 1998 BBC documentary "The Gypsies Are Coming" on Appleby Horse Fair. Appleby Castle is now the private residence of the Nightingale family. Parts of the castle were opened to the public in September 2013 for small private tours, tickets can be booked online or bought at the Grounds Hut on the Gate. Caesar's Tower is built in grey stone rubble and ashlar. It is about high and has four storeys. The main house is in two wings which are at right angles to each other. A semicircular round tower protrudes from the north wall of the north wing and a large square tower is at the south end of the east wing. The gateway to the castle courtyard and two adjoining cottages are listed Grade I. The gateway is in grey stone and battlemented, dating probably from the 17th century. In the grounds of the castle is Lady Anne's Beehouse, which was built by Lady Anne Clifford in the middle of the 17th century. It is a square stone building in two storeys with a pyramid roof and a door on the lower level. The upper level has a pointed arched window on each of three sides and a door on the fourth side. It is also listed Grade I. Two stretches of the sandstone outer walls to the castle dating mostly from the 18th and 19th centuries are listed Grade II, as is the battlemented North Lodge which dates from the 19th century. The grounds around the castle are listed Grade II*.