8 of Europe's coolest castle islands

Why settle for the storybook romance of a castle or the allure of a little island when you can have both? Fortunately, Europe is freckled with castle sites situated on tiny isles.

Citadel settings that came to be for defensive purposes in retrospect now seem tailor-made for tourism. While they're not all fairytale palaces, they're all strongholds or fortresses in one form or another and each offers a chance to experience history in what's essentially an outdoor museum.

As might be expected, France and Italy hold the lion's share of remarkable castle islands, but other destinations will surprise you -- and are worth fitting in. Just remember that some places are easy fodder for over-tourism. The workaround is to make your castle island forays by day -- usually early in the morning or later in the afternoon to dodge tour bus crowds -- but do your overnighting after (or the day prior) in the vicinity rather than on the little castle islands themselves.

1. Le Mont Saint-Michel

It's gorgeous, extraordinary and pretty touristy, but there is arguably no more perfect castle island in the world than Le Mont Saint-Michel in the Normandy region of northern France. Celebrated for its iconic monastery and abbey that reach for the sky-high above a windswept rocky tidal island, the 247-acre site was invincible during the Hundred Years' War and unscathed by World War II. It actually had fortifications long before the feudal period, which imbued it with its present aesthetic.

Since 2014 the castle has been connected to the mainland with the addition of a modern bridge, but if the tide rises high enough it can still become submerged. Your best bet is to visit the island by day but stay in the seaside fortress city of Saint-Malo, an hour's drive west in Brittany, at a fancy French spa hotel.

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2. St Michael's Mount

After the folks clinging to the Mont Saint-Michel threw their support to William the Conqueror back in the day, the first Norman king of England returned the favor by creating a Norman priory on a little island off the coast of the Penzance headland in Cornwall.

Today, the fortress island is linked to the English mainland only by a slender man-made causeway. The coolest part of this Cornish gem, aside from the setting, is the beautiful castle, which has been in the hands of the St Aubyn family since the mid-17th century.

3. San Nicola

Italy's Puglia region is probably best-known for the quirky Trulli houses in Alberobello with their whitewashed walls and signature conical roofs. But the bigger showstopper in the region is arguably plunked 22 miles offshore in the Adriatic Sea -- the Tremiti archipelago. These "earthquake islands" are surrounded by dazzling azure waters.

Craggy San Nicola is home to the 11th-century fortified monastery and abbey of Santa Maria di Tremiti. The hilltop village is also home to the Knights' Tower, Benedictine cloisters and the Church of Santa Maria of the Sea.

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4. Monemvasia

This is Greece's secret stunner: the Byzantine castle island of Monemvasia, in the Peloponnese south of Athens. There is only one entrance to the medieval fortress, which clings somewhat precariously to an elevated island plateau connected to the mainland by a short causeway. Prior to 1971, there was no link at all. While there is evidence of settlement as early as Minoan times, the fortress began to take shape around 583 when locals needed to fend off Saracen raids.

The lower town, framed by steep walls, is a tangle of ancient houses, narrow cobbled streets and tiny chapels, now interspersed with lively shops and cafes. A path leads to the upper town with castle ruins, the lonely Agia Sofia church and stirring sea views. If you stay at Kinsterna, a restored Byzantine manor, you can wake up to views of the iconic "stone boat," as Monemvasia is sometimes called.

5. Castello Aragonese

Capri may be the poster child for pretty Mediterranean sea views (and over-tourism), but the Italian cognoscenti (those in the know) prefer to make a beeline to Ischia, another island in the Bay of Naples but a bit north of Capri. Ischia is where you'll find the rocky volcanic castle islet of Castello Aragonese, connected to the larger island only by a narrow pedestrian causeway.

The imposing rock is awash with lush vegetation except where it's covered with ramparts and other don't-mess-with-me fortifications. It was the tyrant Hiero I of Syracuse who built the original castle in 474 BC, but more fortifications came in the 1400s, courtesy of Alfonso the Magnanimous, with the objective of keeping pirates and other marauders at bay.

6. Old Fortress, Corfu

Corfu is something of an anomaly among Greek islands: Greek to the core, but ruled by Venice for nearly four centuries up until 1797. That means the place is not only beautiful and unusually atmospheric but also packed to the rafters with fortifications because the island was seen as a strategic block to an expansionist Ottoman Empire.

Aficionados of the island will point to Angelokastro on the northwest coast as the most romantic of the island's Byzantine castles, but castle island purists will love the Old Fortress in the town of Corfu itself. A narrow sea channel in the form of a moat separates the Venetian-era citadel from the rest of the town. This sturdy fortress held out against no fewer than three Ottoman sieges.

7. Chillon Castle

Probably Switzerland's most iconic castle, the Château de Chillon is perched on a tiny island on the eastern shore of Lake Geneva in the Swiss canton of Vaud. The lakeside castle dates from about 1005 (although the site has actually been occupied since the Bronze Age) and was built as a fortress to control the strategic road from Burgundy that led to Alpine passes such as the Great St Bernard Pass. There is a circular tower at each corner of the castle, which is surrounded by a moat. A wooden bridge has replaced the original drawbridge.

Fun fact: Visiting the castle island in 1816, Lord Byron was inspired by the story of a medieval Swiss monk imprisoned on the lake island to pen the narrative poem, "The Prisoner of Chillon", and you can still see his signature in the dungeon.

8. Château d'If

This southern French stunner, a fixture in the Bay of Marseille, has both literary and historic appeal as 19th-century French writer Alexandre Dumas used it as the backdrop for much of the action in his novel "The Count of Monte Cristo".

Most famous as a prison, it would be incorrect to call the castle island France's version of Alcatraz because it was actually built with military matters in mind long before it served any penitentiary function. French King François I commanded the rather squat castle's construction in 1524 with a view to repulsing an anticipated attack from the Holy Roman Emperor. The boat ride to the island takes around 20 minutes.

Bottom line

Visiting a mystical European castle can be a great way to explore a new region, take some awesome photos and of course, learn some history -- after all, a lot of Europe's past can seem like something from a fairytale. The above are slightly off the beaten track, too, so you (hopefully) won't be nose to nose with thousands of other tourists.