The fort is believed to date from the pre-Islamic era, and underwent significant renovation in the 9th and 16th centuries during the reigns of Bani Kharous and the Al-Ya'aruba imams respectively. The gate, fence and towers were built during the reign of Sultan Said bin Sultan Al-Bu Saidi in 1834. In 1990, the fort was restored using traditional building materials and period furnishings.
Of the various towers, Al-Wasat Tower (Central Tower) is the most prominent. The castle also features a bridge and contains many rooms for various uses, including the quarters of the Wali, a guard's shelter, a prison, and soldier's rooms. Some wooden ceilings are painted with Qu'ranic inscriptions, and unique Omani and Portuguese antiques are spread through out.
This was the first Omani fort I ever had the pleasure of seeing. It happened to be Eid and I had a nice view from the fort of all the locals going-on-abouts. Friday tends to fill the fort with Jum'a worshippers so coming at prayer times in the afternoon isn't best unless you wanna join in and pray, K?
Bahla Fort: About 30 kilometers west from Nizwa on the road to Ibri lies the mysterious town [Wilayat] of Bahla. Bahla is the home of myths and legends through the centuries. Some people today still believe magic is afoot in Bahla and many Omanis are superstitious when comes to talking about Bahla (my friends included---one of them has a story about a woman who had the legs of a goat????).
This little town is famous for its pottery. The designs are often significant to the locals themselves. There is also the castle of Jabreen worth seeing. This massive three-storied castle was also built during the Al Ya'ruba dynasty of the mid 1600's, and is a fine example of Islamic architecture with beautiful wooden inscriptions and paintings on the ceilings. Other interesting locales between Bahla and Nizwa include the 400 year old village of Al Hamra and the mountainside village of Misfah Al Abreen.
The old Bahla fort with its 12 km wall is the oldest fort in Oman. The fort is believed to have been built in pre-Islamic times and it now undergoing reconstruction sponsored by UNESCO and the site is included on UNESCO's list of World Heritage monuments.Nizwa fort: Nizwa is a verdant oasis city with its blend of the modern and the ancient, and was once the capital of Oman during the 6th and 7th century. One of the oldest cities of the Sultanate, this was once the center of education and art. Nizwa has been an important cross roads at the base of the Western Hajar Mountains connecting Muscat, Buraimi, and the lower reaches of the Dhofar. The Falaj Daris of Nizwa is the largest single falaj in Oman and provides the surrounding countryside with much needed water for plantations.
The city is famous for its historical monuments, handicrafts and agricultural products, has an expansive Souq showcasing a traditional wares such as coffee pots, swords, khanjar, leather goods, silverware, antiques, and household utensils.
The reconstructed Sultan Qaboos Mosque is one of the oldest Masjids in Oman.
Nizwa fort was completed in the 1650's, and was the seat of power during the rule of the Al Ya'ruba dynasty, and is Oman's most visited national monument.
I've personally never seen Nizwa because whenever I go there is it National Day. Or something. Omanis like to close things early. Don't get me wrong, I would love to too, but...
Jalan Bani Bu Ali fort: driving past Sur to the Wilayat [village] of Al Ashkarah there is a 200 year old Masjid [Mosque] with 52 domes as well as the fort, Jalan Bani Bu Ali.
I like its windows, and the fact that it isn't picture-perfect restored like the other forts.
info taken from http://www.uhadventures.com/destination.html