The Sunaysilah Castle is around 300 years old, which was built to provide for the defence system and to guard the city of Sur. The castle is built on a classic square plan atop a hill and has four round watchtowers. The rooms inside the castle have various traditional artefacts like poetry, Quran stands, carpets, etc. The fort offers a magnificent view of Sur, especially of the mosque adjacent to the castle. The castle is located on Highway 23, adjacent to the Sur Court Complex in Sur, Oman. The architecture of the establishment is smooth and plain, with the walls, steps, towers, etc. uniformly built and maintained.