**Carlisle Castle** is a historic fortress located in the heart of Carlisle, England, with a rich history spanning over 900 years. Originally built by William II in 1092, the castle played a pivotal role in border conflicts between England and Scotland. It served as a military stronghold, prison, and royal residence. Today, it is a popular tourist attraction managed by English Heritage, offering visitors the chance to explore its impressive stone walls, medieval keep, and exhibitions that showcase its fascinating history. The castle also provides panoramic views of the city and surrounding landscapes, making it a must-visit landmark in Carlisle.