The castle was built in 1377 as a fortress to guard the road through a narrow mountain pass. From its high windows, guards could see anyone coming up the valley from a long way off. It has thick stone walls, a deep well, a secret tunnel and tiny twisty staircases.
Later, Bran Castle became a royal home. Queen Marie of Romania lived there in the 1920s and loved it - she filled it with flowers, paintings and soft furniture, turning the stern grey fortress into a warm royal house. You can still walk through her bedroom today.
The 'Dracula' nickname comes from an Irish writer called Bram Stoker, who wrote a novel about a mysterious count from Transylvania - the part of Romania where Bran Castle stands. Stoker had never visited Romania himself; he just liked the name and the wild forests. Romanians have lived with the nickname for over a century and turned it into a friendly bit of fun for visitors.
Today, the castle is a museum. Around half a million people visit every year. The most fun part for most kids is climbing the narrow stone stairs from floor to floor and looking out over the forest the same way the medieval guards once did.