the heck?! nothing says castling is a valid move

Nice puzzle.

lol casteling in endgame

u got me w/ that one !  o-o......never thought of that!

Stupide...

very nice

Tricky one!  I was trying every position in which I could force the king to move out....took a while before I thought to castle.  Supposedly though the only way you're about to get this setup is if you played both sides...or just put down the pieces for a puzzle.  But it was a very fun puzzle nonetheless :)

Seen this before... Unfair. =/

Have to say, I didn't get the solutiion as I did not and would never have assumed that a game could reach this point without the castling pieces having been moved-particularly since white's king is completely unprotected.  Unrealistic and a waste of time

this puzzle is a troll

Completely unrealistic. Whoever dreamt this up is exactly that. A dreamer

fail

Same exact thing happened to me once 

can not )))

that was mean :(

clearly reached from the bongcloud opening

Castling is always allowed in a puzzle, unless something in the position indicates there is no way the player can castle, (like: the king must have moved before etc.) This is not the case here.
Please don't call the puzzle stupid if you don't understand it yourself

Never seen a castling mate so late in the game...

WOW