RICH IN HERITAGE, Oman boasts a 5,000-year-old history. As the third-largest country on the Arabian Peninsula, its landscape is dotted with castles and forts - testimony to the country's historic strategic importance. Three of the most important sites have been listed as World Heritage Sites by Unesco, the largest number for a country of its size. A thriving civilisation existed between the 12th and 16th centuries in the district of Al-Blaid. The zone was at the centre of a bustling trade in Arabian horses and frankincense. Remnants of ancient walls, tombs, and mosques - the sultanate's first World Heritage Site - can be found at three archaeological locations at Al Mughsayl. The Bat Tombs of the city of Zafar were discovered in 1976, and are Oman's second listed World Heritage Site. Up to five graves each are contained in the southern tombs, which resemble beehives. They date back to the third millennium BC. Bahla Castle is the country's third World Heritage Site. Dating back to 830AD, it has been rebuilt three times. With 232 watchtowers, the triangular walled compound has been completely restored. Many other castles and forts are worth a visit. Nakhl Castle, located in the Al-Batina region, is believed to date to the pre-Islamic period. Sitting in the foothills of the Western Hajar Mountains, it affords views of the palm farms below. Al-Khandaq Fort, which has a dry moat used as a defensive trench, is located in the town of Walayat, Buraimi, in the Adh-Dhahirah region. It was restored in 1994. Other attractions include museums and galleries in Muscat, the national capital, and its sister city, Mutrah. Muscat, which means anchorage, serves as the antithesis to Hong Kong: there is not a skyscraper in sight. With the exception of two forts dating back to the Portuguese discoveries, the city is full of classical Arabic architecture. There are few shops and no hotels. Key attractions include the Jalali, Mirani and Mutrah forts; the Omani-French Museum; the National Aquarium; and the Bait al-Zubair, a museum with exhibits of Omani heritage. The Mutrah Souk, or market, is one of the best in the region, and gives a glimpse into traditional Omani culture. Several kilometres inland lies the city of Ruwa, home of the National Museum, with displays of jewellery, pottery, traditional costumes, weapons and wooden chests. The Sultan's Armed Forces Museum, which was built in the Bait al-Falaj Fort, is one of the oldest buildings in the district and should not be missed. Owing to its 1,700km coastline, Oman has a long-standing sea-fairing tradition. There is diving in unpolluted waters off Muscat, as well as dolphin and whale watching. Windsurfing, kayaking and traversing are popular in calmer seas. Fishing trips for barracuda, rainbow runners, red snapper sailfish, yellow fin tuna and others can also be arranged. Other popular sports include rock climbing, trekking, cave explorations, desert safaris, bull-fighting and camel racing. How to get there: Gulf Air maintains a hub at Muscat-Seeb International Airport. Hong Kong Passengers can access via Bahrain.