The 10 strongest castles in Greece

Acrocorinth is the mightiest of the Greek acropolis-fortresses, a limestone monolith rising close to 575 metres above ancient Corinth. Three successive lines of wall climb the only feasible approach from the west, funnelling any attacker through three fortified gates, while the Upper Peirene spring, cut deep into the living rock inside the walls, could water a garrison through any blockade.

Byzantines built the core, the Franks added the upper keep, and the fortress passed between Byzantines, Franks, Venetians and Ottomans in turn, almost always by long blockade or by terms, rarely by storm. Leo Sgouros's garrison held out until about 1210; Mehmed II needed a four-month siege to take it in 1458; Morosini's Venetians recovered it in 1687, and the Ottomans returned in 1715.

The palace that gives this entry its name is largely a 1937-40 Italian reconstruction, rebuilt by the architect Vittorio Mesturino after the medieval original was gutted by a gunpowder explosion in 1856. The genuine fortress is the surrounding circuit of Hospitaller walls around Rhodes old town, among the most advanced artillery-age defences in Europe, with deep dry moats, thick angled bulwarks and each sector assigned to a different 'tongue' of the knightly Order to hold.

Those walls threw back a massive Ottoman assault in 1480. In 1522 Suleiman the Magnificent returned with an army said to number a hundred thousand; after roughly six months of mining and bombardment the knights marched out under terms. The stronghold was worn down and negotiated away, never carried by storm.

Methoni guards a rocky promontory nearly a square kilometre across, sea on three sides and a broad man-made moat severing it from the mainland, one of the finest Venetian sea-fortresses in Greece, with massive gates, sturdy curtain walls, square towers and the sea-girt Bourtzi tower covering the harbour approach.

It held Venice's 'Modon' for three centuries. In August 1500 the fleet and army of Bayezid II besieged and stormed it; the population was killed or enslaved and Venetian rule ended. Venice recovered it during the Morean War in 1686, only to lose it to the Ottomans again in 1715.

Chlemoutsi is the most ambitious and best-preserved Frankish castle in Greece, raised in 1220-23 by Geoffrey I of Villehardouin to command the coastal plain of Elis from a dominant hill. Its strength is architectural mass: a great hexagonal keep of vaulted two-storey halls wrapped around an inner court, screened by an outer enceinte.

It was built before the gunpowder age, though, and was rarely tested by a serious defence, it passed to the Byzantines in 1460, to Venice in 1687 and back to the Ottomans in 1715, largely by capitulation. In 1825 Ibrahim Pasha's Egyptian cannon breached the southern wall after only a brief bombardment, and the ruined south tower still shows the wound.

The Fortezza is a purpose-built artillery fortress, its foundation stone laid in 1573 and the work finished around 1580 to Sforza Pallavicini's design: angled bastions linked by thick curtain walls sloped outward to deflect shot, the most modern siege-resistant engineering of its day. Its record is less impressive than its trace. When an Ottoman army invested Rethymno in the autumn of 1646, the townspeople crowded inside, but disease, hunger and dwindling ammunition told; after some six weeks the Venetians surrendered on terms on 13 November, a sophisticated fort that never withstood the siege it was designed for.

Angelokastro sits on the highest, most precipitous point of Corfu's northwest coast, a Byzantine crag-castle whose defence rests more on sheer cliff than on elaborate walls. Small it may be, but its war record is the best on this list: as the strongpoint of Corfu's defensive triangle it helped repel every Ottoman attempt on the island, the great sieges of 1537 and 1716 and the raid of 1571, with villagers crowding onto the battlements beside the garrison. Despite repeated assaults over the centuries the fortress was never taken. Here the 'never captured' reputation is sober fact, not legend.

Ioannina is a large fortified citadel on a rocky headland thrust into Lake Pamvotida, water guarding its flanks and a moat, fed from the lake, closing the landward side; within it a separate inner fortress, the Its Kale, forms a keep in miniature. The Normans under Bohemond first fortified the site in 1082, the Ottomans took the town by treaty in 1430, and Ali Pasha rebuilt the walls into their present massive form as his personal stronghold. That defiance ended in 1822, when a Sultan's army besieged and finally destroyed him here; Greek troops took the castle in 1913.

Platamon commands the coastal defile below Mount Olympus where the road squeezes toward the Vale of Tempe, a Byzantine-and-Frankish castle whose tall octagonal tower-keep still dominates the pass. Its walls and towers made it a genuine strongpoint on a strategic throat rather than a great fortress. Like most Greek castles it changed hands by conquest: the Lombard knight Rolando Piska rebuilt it for the Franks after 1204, Theodoros of Epirus retook it for Byzantium in 1218, and the Ottomans seized it in 1385, keeping it in good repair for the road it guarded.

Patras Castle crowns a low hill above the gulf on foundations laid by Justinian after the earthquake of 551, a triangular circuit of towered walls and moats enclosing some 22,000 square metres with a moated inner keep. In the Byzantine centuries it was strikingly resilient, beating off Slavs, Saracens and Normans, the celebrated repulse of the great Slav-and-Arab siege of 805 was credited to Saint Andrew. Its later record was ordinary: the Franks took it in 1205, Constantine Palaiologos in 1430, and the Ottomans in 1458, who held it until the garrison was handed over to a French force in 1828.

Old Navarino, or Palaiokastro, is a Frankish castle built between 1278 and 1289 by Nicholas II of Saint-Omer on a steep height guarding the north entrance to Navarino Bay, later given a lower Venetian enceinte. Its natural position is strong, but as a fortress it is the slightest here, modest in scale, much ruined, and never the scene of a great defence. Its story is one of obsolescence rather than heroic siege: after the new fortress of Niokastro was raised across the bay in 1573, the old castle lost its purpose, was left to decay and slipped out of the military reckoning.