Burg Kronberg was founded in the 12th century but was partially destroyed during the bombing of 1943. It was reconstructed though in a simplified version. There are only three main buildings today. You can climb the tower if you like, but we decided not to do it because it was so hot that day. The climb to the burg itself is already quite intense. It took us even longer because the sign pointing to it was absolutely minuscule but we got there in the end.
Nowadays the burg is perhaps best known because of Victoria, Princess Royal, the later Empress Frederick. She received the burg as a gift from her son the Emperor in 1891. She had the burg restored to what it would have looked during the times of the Lords of Kronberg (medieval times) and essentially created the museum function that we see today. Victoria left the burg to her daughter Margaret and she and her husband restored the burg even more. From 1969, the burg has been in the hands of the government.
You can only enter the museum part of the burg with a tour guide and our guide just happened to speak excellent Dutch (he was a German who had lived in the Netherlands). The entrance fee of €6,00 includes the tour and is quite reasonable. Their shop even had a few books. Read more information on their official site.