One fascinating fact about Alcazar is that each puzzle has a unique solution. Because of that, there is always a way to solve them using pure logic.
It's sometimes hard to believe, like in the example right here. It's an empty room, but there is only one way to enter, visit the 16 squares once, and exit. You can try directly here: simply draw lines with your mouse!
Do you see the solution? How can we prove that it's the only one? Have fun!