The most defensible medieval castle design?

Yes, a castle is part of a system. Other parts of the system include logistics trains and whatever combined arms (infantry, cavalry, skirmishers, etc.) you can muster. An undefended/insufficiently defended castle will fall, but a properly garrisoned one will allow you to move forces into and out of it as necessary, and, one hopes, eventually allow you the option of falling on some exposed part of the foe, harrying his communications, or something.

An island castle, by sheer logic.

Hohensalzburg was not the inspiration for the Disneyland castle. Neuschwanstein was. And I don’t think Neuschwanstein was even intended to be a fortress like most castles were; it was designed and built strictly as a showpiece. King Ludwig of Bavaria wanted to incorporate features from the thirteenth and fourteenth century, but since he was living n the mid-1800s, his castle would have vulnerable to more than arrows and lances.

You want to see REAL excess, check out Schloss Linderhof!
~VOW

Unless islands are in short supply, and then you make do with what you have. This is why there were many more mountain castles in Japan than island ones.

I was responding to saucywench’s post, which, I’m pretty sure, points to Neuschwanstein.

Exactly so; again, I noted its shell-thin walls, and compared it to another purely ornamental “castle,” Blenheim Palace. It is, however, nicely sited on a bit of a crag of rock, and so isn’t totally worthless for defense!

Pretty! Like a wedding cake! (Comparison not meant to indicate anything about the crumbs within…)

I’d suggest Saint Malo that is surrounded by a sandy floodplain. So attacker can’t reach it with ships or army.

Of interest:

Just out of curiosity, are there any castles or fortifications located at the edge of a waterfall, like this? That’s from a video game, and maybe the water wouldn’t make it very practical, or impossible to build. But any real life castles like that?

Cool picture.

I suspect that it would be very difficult to build, but not necessarily impossible given the right conditions. It probably wouldn’t last very long, though, as waterfalls do tend to erode. But it would be damned defensible while it lasted.

Oh, holy God, that is so damned COOL! I knew I wasn’t the only one insane enough to think this! Every time I go to Disneyland, I take a bit of time to sit comfortably in front of the castle, and, in the privacy of my disordered mind, go through exactly those kinds of tactical exercises!

(“TEWT: Tactical Exercise Without Troops.” Hypothetical problem-solving, on paper or in the field, deploying imaginary forces to solve real tactical problems. FUN!)

My best design:

A fortified stronghold raised within the 10-mile stretch of swamps separating Ramree Island and the Burmese mainland. Light boats might reach it but don’t try marching through the swamp. Anywhere from 300 to 900 Japanese soldiers were eaten by crocodiles in just one evening in 1944.

Um… an underground castle.

Not many medieval examples, considering the technology they had (candles for light use up oxygen awfully fast, particularly when paired with any significantly-sized garrison force), but that’s the dominant idea behind modern fortifications. Pre-modern, any fort built underground would be virtually impossible for foreign invaders to take without inside help. Build it where there is water and stockpile food, and sieges are difficult.

Of course, if an invader collapses the opening(s), that’s a problem. You could dig your way out, sure, but it would be a “win the battle, lose the war” scenario. Any underground bunkers during pre-modern times would be purely for defense and not very effective at controlling the surrounding countryside. Just another reason why there aren’t many examples of such- castles were all about controlling the countryside with a place to retreat to when a superior force came knocking.

JDthJD, google images for San Juan de la Peña. Not quite underground and it’s not a castle, but part of the reason it’s generally considered as “the birthplace of the kingdom of Aragon” is that it wasn’t so much unbreachable as unreachable, which made it a good base for the “upstarts”.

Beaumaris Castle in Anglesey, Wales would have been a bastard to attack if it had ever been finished.

Whatever their failings as a religious organization, the Cathars could build a freaking castle:
http://www.catharcastles.info/queribus.php?key=queribus

They could occupy castles like gangbusters, but they probably didn’t build any :). Queribus is mentioned all the way back in 1020, more than century before Catharism as such was a going concern ( assuming it was, which is a slight controversy ).

The problem was that the Japanese were the defenders.

There were several large underground cities in Cappadokia in Turkey. Like Derinkuyu, for instance. I can’t find any information about whether they ever were invaded or not, but it seems they were built primarily for defensive purposes.

I don’t know about the castle defenses specifically - but for location alone, Mont Saint-Michel has to be a strong consideration. And pretty damn cool too.

Very cool. But how do they get fresh water?