Best Hidden Gems in Kent
Written by UK Hidden Gems Editorial
Updated 5 August 2026
The best hidden gems in Kent are Abbot's Cliff Sound Mirror, Slough Fort, Folkestone White Horse, Reculver Towers and Roman Fort, Dymchurch Martello Tower, The Bishop's Palace, The Underground Hospital and Kingsgate Bay Sea Arch.
Kent has faced the Continent for two thousand years, and much of this set is about defence and the sea. The eight places here run along the coast and the North Downs, taking in a concrete sound mirror built to listen for enemy aircraft, a Napoleonic Martello tower, a Victorian estuary fort, and the wartime tunnels beneath Dover Castle from which Dunkirk was directed.
Alongside the defences stand older and stranger things: the twin medieval towers of a church inside a Roman fort at Reculver, a natural chalk arch on the Thanet coast, a ruined bishops' palace by the Medway, and a modern white horse cut above the Channel Tunnel. Some are free and open at any time; others open on set days or as part of a wider castle visit, so a quick check of opening hours helps.
Between the coast and the North Downs, they trace two thousand years of facing the Continent. Here are eight hidden gems to seek out across Kent.
Abbot's Cliff Sound Mirror
Photo: Barry Hunter via Geograph.org.uk
The Abbot's Cliff Sound Mirror stands on the clifftop between Folkestone and Dover, a slab of grey concrete with a shallow bowl scooped into its face, about six metres across and angled out toward the Channel. A short walk along the cliff path from the old coast road brings you to it, with a small concrete structure beside it that once held listening equipment.
The idea was to catch the sound of approaching aircraft out over the water before they could be seen, an early attempt at air defence built in 1928 and made redundant within about a decade once radar arrived. It stands alone on the grass, the sea below.
Slough Fort
Photo: David Anstiss via Geograph.org.uk
Slough Fort is a Victorian artillery fort at Allhallows, on the Isle of Grain, built to guard the approaches to the Thames estuary. A brick, D-shaped fort ringed by a dry moat, with two later wing batteries added to either side, it once mounted heavy guns aimed out over the river.
It stands now within a holiday park, cared for by a preservation trust, and its gun emplacements, moat and casemates are opened to visitors on occasional open days rather than every day. It is a protected monument, a solid reminder of the estuary's old defences.
Folkestone White Horse
Photo: Helmut Zozmann via Geograph.org.uk
The Folkestone White Horse is a large figure of a standing horse on the chalk slope of Cheriton Hill above Folkestone. Unlike the ancient hill figures, it was made in 2003, designed by a local artist and formed of pale blocks set into the hillside rather than cut into the bare chalk.
It looks down over the Channel Tunnel terminal and is a landmark for travellers arriving in Britain, standing about ninety metres long on the open down, best seen from below or from the passing trains and roads.
Reculver Towers and Roman Fort
Photo: Chris Whippet via Geograph.org.uk
Reculver is a pair of tall medieval church towers standing on the low cliffs near Herne Bay, set within the walls of a Roman fort. The Romans built the fort in the third century to guard a channel that then ran behind the Isle of Thanet, and later a Saxon monastery and then a church rose inside its walls.
The church was abandoned as the sea ate away the land, and it was mostly pulled down in the early nineteenth century, but its twin towers were kept as a landmark for ships and still stand out along the coast. It is a free English Heritage site, with the flint fort walls around it.
Dymchurch Martello Tower
Photo: Oast House Archive via Geograph.org.uk
The Dymchurch Martello Tower is one of the round brick towers built along the Kent coast against the threat of invasion by Napoleon, standing on the High Street at Dymchurch. Restored and looked after by English Heritage, it shows how the tower worked, from the store room at the base up to the garrison floor and a cannon mounted on the roof.
The thick, gently tapering walls were made to shrug off attack. Steep stairs climb inside to the gun on top, one of the best-preserved of the many towers that once lined this shore.
The Bishop's Palace
Photo: Dylan Moore via Geograph.org.uk
The Bishop's Palace is a ruined medieval palace of the bishops of Rochester, standing beside the River Medway at the village of Halling, next to the parish church. The main survival is the tall western wall of the great hall, standing several metres high with three Gothic windows, with the rest surviving as low walls and buried foundations.
A residence stood here from the eleventh century, rebuilt over the following centuries, before it was largely pulled down and turned to other uses. It is a protected monument, recently conserved, a quiet spot on the riverside in the village.
The Underground Hospital
Photo: Graham Horn via Geograph.org.uk
The Underground Hospital is part of a network of wartime tunnels cut deep into the white cliffs beneath Dover Castle. In the Second World War these tunnels held a command centre and a hospital, from which the evacuation of Dunkirk was directed, and the hospital section has been laid out to show its operating theatre, wards and corridors, with recreated sounds and effects.
It is visited on a guided walk as part of a day at Dover Castle, cared for by English Heritage, and gives a vivid sense of what it was like to work underground through the bombing.
Kingsgate Bay Sea Arch
Photo: Colin Park via Geograph.org.uk
The Kingsgate sea arch is a natural arch worn through the white chalk at Kingsgate Bay, on the Thanet coast between Broadstairs and Margate. The sea has cut clean through a spur of the cliff to leave the arch standing on the sand, which can be walked around at low tide.
The soft chalk is prone to falls, so the arch changes over time. It makes one of the best-known sights on this stretch of coast, framed by the white cliffs, and is best reached at low tide from the bay.
FAQs
What is the Abbot's Cliff sound mirror in Kent?
The Abbot's Cliff sound mirror is a concrete dish about six metres across, built in 1928 to catch the sound of approaching aircraft out over the Channel before they could be seen. It stands on the clifftop between Folkestone and Dover, and radar made such mirrors redundant within about a decade.
Can you walk under the Kingsgate sea arch?
Yes, at low tide you can walk under the Kingsgate sea arch. The natural chalk arch at Kingsgate Bay stands on the sand and can be walked around when the tide is out. The chalk is soft and prone to falls, so the arch slowly changes shape over time.
How do you visit the Underground Hospital at Dover Castle?
The Underground Hospital is seen on a guided walk as part of a day at Dover Castle, which English Heritage runs. The wartime tunnels, cut into the white cliffs, held the command centre from which the Dunkirk evacuation was directed.
Is Reculver free to visit?
Yes, Reculver is free to visit. The twin medieval towers set within a Roman fort near Herne Bay are a free English Heritage site, open on the low cliffs with the flint fort walls and earthworks around them.
Conclusion
Facing the Continent, Kent has always been a front line, and these eight gems tell that story. There is the concrete ear of the Abbot's Cliff sound mirror, the Napoleonic Martello tower at Dymchurch, the Victorian estuary guns of Slough Fort, and the tunnels beneath Dover Castle where Dunkirk was run.
Older and stranger sights sit among them: the twin church towers inside the Roman fort at Reculver, the natural chalk arch at Kingsgate, the ruined bishops' palace by the Medway, and the modern white horse above the Channel Tunnel. Some are free and open at any time, like Reculver and the sea arch; others open on set days or as part of a castle visit.
Between the coast and the downs, they make a rich run of history. These are the places to seek out across Kent.
