This is the Saxon's shield that they had while they lived in Transylvania. This of course has meaning to them and it is still seen and used by the descendants of these Saxons. One of the cities that is represented by the seven castles is Sighisoara.
It is one of the seven castle cities which has a link to Dracula -- the real Dracula, as in Vlad Tepes, upon whom the writer Bram Stoker based the main character when he wrote his famous novel. Dracula was published in England is still popular more than 100 years later.
This is an image not of Count Dracula, but rather of Vlad Tepes III who was born in Transylvania. He was a younger son of the exile prince of Wallachia, and wasn't expected to become prince of Wallachia. After the murders of his elder brother and father, though, he did.
It is important to note that he was not a prince of Romania but rather a prince of Wallachia. He was not a prince of Transylvania at any time either.
The point is that the idea of Dracula makes for good writing. To be honest the idea makes good money since the fictional character count Dracula is still in the movies of Hollywood. Of course, the Russians and the Germans and the Romanians have also written a lot about Vlad Tepes. Depending on whom you read, you will find some very different points of view about Vlad Tepes. Jump into any good history book to find out more about Transylvania.