(CNN) — Shoot an arrow in Germany, and more often than not, you'll hit a castle.
It may sound preposterous given the country's reputation for method and organization, but we still don't know how many castles there are on German soil.
There are some castles, though, that stand out because of their beauty, their history, their location or simply because they've entered popular culture through a quirk of fate.
Here are 10 of Germany's best castles to see when you travel here:
The impregnable prison: Colditz
Even if you haven't read the book, watched the movie or played the "Escape From Colditz" board game, chances are you've heard of Colditz Castle.
Built strategically on a cliff in 11th-century Saxony, it had been used as a military outpost, a zoo and a mental hospital before it became a prison for political prisoners under the Nazis. Deemed escape-proof, it then held officer POWs during World War II.
Among those held there were British flying ace Douglas Bader, Winston Churchill's nephew Giles Romilly and Viscount Lascelles, first cousin of Queen Elizabeth II.
Despite its impenetrability, there were many successful escape attempts.
Among others, British Lt. Airey Neave, later MP, crawled through a hole during a theater performance; French Lt. Pierre Mairesse-Lebrun was catapulted out; and British Capt. Pat Reid cut through the bars of a kitchen window and later wrote a bestselling memoir that introduced Colditz into mainstream culture.
The romantic ruin: Heidelberg
Each year, the Heidelberg ruins attract around a million visitors from all over the world.
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"Nothing is greater than fallen might" wrote Victor Hugo about the ruins of Heidelberg Palace, which, like a good bottle of wine, has aged remarkably well.
Mark Twain, another fan, wrote: "A ruin must be rightly situated to be effective. This one could not have been better placed."
Constructed of pink-brown sandstone that turns bubblegum-colored at sunset, surrounded by woods and terraced for multiple views over Heidelberg and the lush Neckar Valley, this is the most romantic of German castles.
If you need proof, find the Elizabeth Gate. This dainty baroque arch with delicate carvings was erected in one night in 1615 by Elector Frederick V, as a surprise gift for the birthday of his wife, Elizabeth Stuart of England. What gesture could be more dewy-eyed than that?
The opera set: Wartburg
Martin Luther translated the Bible's New Testament into German at Wartburg castle in Eisenach.
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Richard Wagner fans are familiar with Wartburg Castle from his opera Tannhäuser. It's in the castle's Troubadour Hall that the knight hero enters a "Battle of the Bards" singing contest in Act II.
Indeed, the owners of Wartburg -- a UNESCO-inscribed Romanesque gem dating back to 1067 -- were patrons of the arts and that singers' hall still exists today, refurbished through the eyes of 19th-century romanticism.
Still, there's much more to see, most notably mosaics that portray its most venerated resident, St. Elizabeth of Hungary, who was canonized in 1235. Today, though, its main attraction is Martin Luther's office-in-exile. This Protestant pilgrimage spot is where the great reformer translated the New Testament into German, enabling the masses to interpret the text for themselves.
The fairytale: Neuschwanstein
If you thought that Neuschwanstein Castle has an uncanny resemblance to Sleeping Beauty's castle in Disneyland, you'd be right. It did serve as the blueprint.
Neuschwanstein was built by King Ludwig II, the "Mad King" of Bavaria in 1880, "in the authentic style of the old German knights' castles," as he himself described. King Ludwig modeled it on Wartburg, whose Troubadour Hall is replicated here with much more aplomb.
Neuschwanstein's multiturreted silhouette embodied an abstract Germanic ideal, the result of combining medieval designs with 19th-century perceptions of what such designs ought to look like.
Add to this a magnificent setting on a ridge facing the Tyrolean Alps, and it's no wonder Neuschwanstein is one of the most photographed buildings in the world and served as an inspiration to Walt Disney and his animators.
The island fort: Schwerin
Schwerin Castle is situated on an island in a lake in the town of Schwerin.
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We think of a castle perched high on an inaccessible ridge, looking impregnable and fearsome. In the absence of mountains, castles use moats as defenses, but Schwerin Castle, located in the plains of northern Germany, goes one better by occupying an island in a lake.
There's been a fortified settlement at that spot since AD 973, but the current jewel of a building stems from the 19th century and comes complete with a ghost in the cellar ("Little Pete," first sighted in 1747).
When the owner, the Duke of Mecklenburg, abdicated after World War I, no one knew what to do with the castle or cared enough to maintain it.
Its luck turned in 1990, when it became the seat of the regional assembly, and this beautiful castle and its gardens were fully restored to their original grandeur.
The monster's lair: Frankenstein
The unassuming ruins of the 13th-century Frankenstein Castle overlooking Darmstadt bask in the fame of its name. Historians doubt whether Mary Shelley, author of the horror novel, ever saw it, let alone set foot on it.
Although she did cruise on the Rhine in 1814 and passed within 10 miles of the ruins four years before her book came out, the castle doesn't appear in her memoir of the trip.
However, Frankenstein Castle was the birthplace of Konrad Dippel, an alchemist who claimed to have invented the elixir of life and may have experimented with cadavers.
Shelley could well have heard of Dippel's quest -- which by then must have become grotesque in the retelling -- and based Dr. Frankenstein's character on him.
Nowadays, it's a sought-after destination around Halloween with sold-out parties featuring 100-odd monsters that include werewolves, vampires and modern horror villains such as Freddy Krueger and Michael Myers.
The youth hostel: Altena
Altena Castle, 40 miles northeast of Cologne, houses a youth hostel dating to 1912.
Many castles have become luxury five-star hotels, but Altena Castle, 40 miles northeast of Cologne, houses a youth hostel that dates from 1912.
That's when Richard Schirrmann, a teacher by profession, opened the world's first youth hostel in the newly renovated castle. In 1919, right after World War I -- where Schirrmann fought in the Vosges front -- he founded the Youth Hosteling Association, believing that bringing young people together minimized the chances of another bloody conflict.
Today, Altena Castle is a double monument to Schirrmann's idealism -- firstly by incorporating a World Youth Hostel Museum in its premises and secondly by still providing the young and the young at heart with affordable accommodation in a genuine, 800-year-old castle.
The grande dame: Meersburg
Overlooking the shores of Lake Constance, Meersburg Castle claims to be the oldest still-inhabited castle in Germany. According to legend, it was built in AD 630 by Dagobert, a king in the Merovingian dynasty. The central keep, Dagobert's Tower, is named after him.
The various residents have modified it according to the whims of their respective eras. Today, it looks part Baroque, part Renaissance or part Gothic, depending on the viewing angle, so much so that it's difficult to think of it as a homogeneous entity rather than as a collection of individual interlocking buildings.
On the plus side, it's been well-maintained because it's been more or less continuously inhabited -- mostly by the bishops of Constance -- except for a short period after the Napoleonic Wars.
The medieval condo: Eltz
Tall, slender and rising perpendicularly on a 700 meter-high rock outcrop with the river Elzach snaking at its feet, Eltz Castle is arguably the most eye-catching castle in Germany.
Towering up to eight stories high, it became widely known when it appeared on the back of the old 500-Deutschmark note. Blessed with an uneventful existence, it was never raided or breached and has remained relatively pristine.
Peace was also reflected internally: in 1268, the Eltz family line split in three and each branch lived in a separate wing with communal rules more akin to a modern condominium.
Only in 1815 did the property return to a single heir, but by then the rivalry of keeping up with the neighbors had resulted in six centuries of better-than-thou lopsided construction that's given the castle today's fascinating appearance.
The showpiece: Hohenzollern
Hohenzollern Castle, on top of a gentle hill 30 miles south of Stuttgart, belonged to the family of the German Kaiser yet was hardly a strategic stronghold. To the contrary, the castle was destroyed twice, passing to Austrian control until 1798 after which it crumbled to a ruin.
With the ascendancy of Prussian military in the 19th century, however, the Hohenzollerns needed to strengthen their bonds across Germany, so they built their version of a medieval castle as an ancestral showpiece.
No one from the Kaiser's family ever lived there, and only toward the end of World War II did the last Hohenzollern descendants arrive from Prussia, fleeing the Soviet Army. Built to look photogenic, it's no surprise that the castle has served as a backdrop in several movies, including Stanley Kubrick's "Barry Lyndon."