Fort Denison, also known as Muddawahnyuh, is a significant historic island fortress located in Sydney Harbour, accessible primarily by ferry from Circular Quay, Sydney. While some areas are navigable independently, a guided tour (often included with ferry tickets) is highly recommended to fully appreciate its rich history as a former penal site and defensive fortification. The fort involves stairs and uneven surfaces, which may limit accessibility for those with mobility challenges. It generally operates year-round, but visitors should check ferry schedules and seasonal opening hours, as adverse weather can impact services. The approximate cost typically ranges from AUD $20-$40+ for a combined ferry and entry ticket, excluding food and drinks at the island's cafe. A typical visit duration, including ferry travel and exploration, is around 2-3 hours. Key highlights include panoramic views of Sydney Harbour, the Opera House, and Harbour Bridge, alongside a daily 1 pm cannon firing tradition.