Allington - 2 miles north west of Maidstone
In 1951 following the comprehensive restoration the site was taken over by the Carmelite order who do not open the castle to the public.
http://www.medievalcastles.net/england/allington.htm

Bodium Castle
The appearance of Bodiam Castle is exactly how most people imagine a medieval castle should look like, with its square of walls, a round tower at each corner, and a square tower midway along each wall, entirely surrounded by a moat.
http://www.castlexplorer.co.uk/england/bodiam/bodiam.php#castle

Chiddingstone Castle – Near Edenbridge
Chiddingstone Castle, a squire's home with Tudor roots, hidden in lovely unspoiled Wealden countryside yet only 35 miles from London, was once the seat of the Streatfeilds, and has retained an intimate, timeless appeal through all changes.
http://www.chiddingstone-castle.org.uk

Cooling Castle Nr Rochester
A romantic, tree shrouded, ruined castle( c.1381), of considerable landscape importance, although sadly now of very limited extent. The ruins of the castle have been landscaped and turned into very attractive pleasure grounds. Flooded moat and walled kitchen garden remain.
http://www.york.ac.uk/depts/arch/landscapes/ukpg/sites/coolingc.htm

Deal
Deal Castle was built by Henry VIII in 1539-40 as an artillery fortress to counter the threat of invasion from Catholic France and Spain. It was the largest of three forts constructed to defend the area of safe anchorage known as the Downs. The other forts were at Walmer, now the official residence of the Lords Warden of the Cinque Ports, and Sandown, which was largely demolished in the middle of the 19th century.
www.castlexplorer.co.uk/england/deal/deal.php

Dover
One of the largest castles in the country, strategically located at the shortest crossing point to continental Europe, Dover Castle has played a prominent part in national history. Its origins lie in the Iron Age, and a Roman Lighthouse and Anglo-Saxon church can still be seen within the grounds
http://www.castlexplorer.co.uk/england/dover/dover.php#castle

Hever
Hever Castle is an attractive fortified manor house surrounded by a moat. The original moated castle was built in 1270 and consisted of a massive gatehouse and a walled bailey, approached by a wooden drawbridge.
http://www.castlexplorer.co.uk/england/hever/hever.php#castle

Leeds Castle
A CASTLE FOR ALL SEASONS AND ONE OF THE MOST ROMANTIC AND HISTORIC BUILDINGS IN THE LAND. Listed in the Domesday Book, this castle has been a Norman stronghold, a royal residence for six of England’s medieval queens, a palace of Henry VIII, and a retreat for the powerful and influential.
http://www.leeds-castle.com

Rochester
In 1087, Gandulf, Bishop of Rochester, started the construction of Rochester Castle at a strategic site guarding the crossing of the River Medway on the main route to the Channel ports. The roof and all the floors are missing from the keep, but you can still climb to the top. The castle grounds are now maintained as a park.
http://www.castlexplorer.co.uk/england/rochester/rochester.php#castle

Scotney
The building of Scotney Castle is believed to have commenced c1378, and is attributed to Roger Ashburnham. Although it’s appearance is that of a regular fortress, roughly rectangular in shape (actually rhombus, its northern perimeter being slightly longer than the others) with circular towers at each corner, it was predominantly designed as a well fortified house.
http://www.theheritagetrail.co.uk/castles/scotney%20castle.htm

Upnor
Upnor Castle is a well preserved gun fort, built between 1559 and 1567 on the orders of Queen Elizabeth I to defend her warships at anchor in the reaches of the Medway and Chatham Dockyard. The castle is fronted by a water bastion jutting out into the River Medway.
http://www.castlexplorer.co.uk/england/upnor/upnor.php

Walmer
Walmer Castle was built by Henry VIII in 1539-40 as an artillery fortress to counter the threat of invasion from Catholic France and Spain. It was one of three forts constructed to defend the Downs, an area of safe anchorage protected by the Goodwin Sands
http://www.castlexplorer.co.uk/england/walmer/walmer.php#castle