Eastern Kent: The highlights - Telegraph Dover Castle is an arresting sight, an encrustation of towers and walls silhouetted on a hilltop, squatting above the town and looking for trouble in all directions. The mound itself is like a core sample of English history. It almost certainly started life as an Iron Age fort, and it still has a fine octagonal lighthouse built by the Romans. It once had a Norman keep and at its apex sits a sturdy Saxon church. But it's the fascinating tours of the secret Second World war tunnels that are the chief draw for Castle visitors. Sunk deep into the chalk cliffs these tunnels were the HQ for Operation Dynamo - the evacuation of troops from Dunkirk. The tour takes in operations rooms, hospital wards, dormitories, kitchens and mess rooms, some restocked with period equipment and furniture. More information: 01304 211067; english-heritage.org.uk. Tours are very popular and cannot be booked (except for groups of 11 or more), so arrive early. See the website for opening times. Operation Dynamo: Reliving the miracle of Dunkirk Sophie Campbell inspects the underground HQ at Dover Castle where, 70 years ago, Operation Dynamo was devised. Rochester With its sturdy Norman cathedral, and elegant precincts, Rochester has as much to offer as Canterbury, arguably more so, as it also has strong links with Charles Dickens. The cathedral plays a central role in The Mystery of Edwin Drood, while the Guildhall, now a museum, is where Pip was apprenticed to the blacksmith Joe Gargery in Great Expectations. Restoration House, the inspiration for Miss Havisham's Satis House in Great Expectations, is also open to the public on selected dates throughout the summer. Near the cathedral are the ruins of Rochester Castle, overlooking the Medway - a reminder of the days when foreign raiders had to be forcibly repelled, as the Dutch were in 1667. But the whiff of cordite is a distant memory. Modern Rochester is friendliness personified, proud of its history and proud of the Dickens connection. Not to be outdone, neighbouring Broadstairs holds a Dickens Festival each June. More information on visitthanet.co.uk; restorationhouse.co.uk Margate The town's Georgian terraces and squares are testament to its 18th century popularity, when visitors came by coach and sailing ship from London and surrounds to enjoy the fine beaches and bracing air. Recently its fortunes have revived with the opening of the Turner Contemporary gallery in 2011 - championed by Tracey Emin, Margate's most famous daughter. Behind the gallery is the Old Town, an attractive area of narrow cobbled streets which are home to a thriving community of independent shops specialising in vintage and retro, art galleries and cafés. And work will start this year to rebuild the historic Dreamland theme park with its Grade II listed roller-coaster. More information on visitthanet.co.uk Chatham Dockyard Set on the River Medway, the Historic Dockyard Chatham was, from the 17th century onwards, the base and building yard for the fighting ships of the Royal Navy. At one point it employed some 2,000 men from 26 different trades, and the buildings associated with their work are still there, forming the backdrop for films and TV series from Les Miserables to Call the Midwife. When Chummy dons her beret and cycles precariously along the cobblestones past what look like the old East End docks, she's here, among evocatively named buildings such as the Hemp Houses, Spinning Room, and the Victorian Ropery. Visitors today can explore these historic buildings, as well as a variety of ships from the Victorian sloop HMS Gannet to the Cold War submarine HMS Ocelot and the navy's last operational destroyer, HMS Cavalier (01634 823800; thedockyard.co.uk). Joanna Symons