never!
Medieval castles.
If you follow the link below, you will come to a list of links to lists of castles by country.
There is nothing different between todays castles and medieval time castles. Today's castles were built in medieval times.
Here’s a list of questions about castles: What were the primary purposes of castles in the medieval period? How did the architectural features of castles evolve over time? What are some famous castles around the world and their historical significance? How did the living conditions within a castle differ for nobility and commoners?
The welsh medieval castles were big and gray.
A keep is a very important part of a medieval castle. It is the castles finial defence from attackers.
Medieval times
in the late medieval period many medieval castles did have a primitive type of cannon.
Castles were invented in medieval times.
There are no genuine medieval castles in the USA, because the Americas were not discovered until after the medieval period had ended. There are the "fairytale" Disney castles and some modern attempts at reconstructing medieval castles, but no genuine ones.
erm it's not a lot but this may be of help http://www.dialsolutions.com/n-ycurric/castles/type/0/html.htm
Who is most important in medieval history - kings and emperors. Where do they live - in castles.