The King's Highway winds its way through the different ecological zones of the country, including forested highlands, open farmland plateaus, deep ravines, the edge of the eastern desert, and the warm tropical Gulf of Aqaba.
Lining both sides of this 335-kilometer (207-mile) thoroughfare is a rich chain of archaeological sites that reads like an index of ancient history and a biblical gazetteer -- prehistoric villages from the Stone Age, biblical towns from the kingdoms of Ammon, Moab and Edom, Crusader castles, some of the finest early Christian Byzantine mosaics in the Middle East, a Roman-Herodian fortress, several Nabatean temples, two major Roman fortresses, early Islamic towns, and the rock-cut Nabatean capital of Petra.

The best way to explore the Kings' Highway today is to rent a car in Amman or Aqaba and spend two or three days on the road. Many new service facilities make this an easy and enjoyable trip, including hotels and motels at Petra, Kerak and Madaba, and many new restaurants, tourist service stations, and rest stops along the way.

From Amman, the King's Highway winds southwards through the lush wheat lands of the biblical kingdom of the Ammonites, where major sites to be visited include Hisban, Dhiban, Madaba, and Aroer. The 6th Century mosaic map in Madaba is the oldest surviving map of the Holy Land. Ten minutes west of Madaba is Mount Nebo, from where Moses viewed the Holy Land. Half an hour south is the hilltop Herodian fortress of Macherus (el_Meshneqah, or "the gallows," in Arabic), where Herod Antipas imprisoned and beheaded John the Baptist.

The Kings' Highway then winds through the picturesque, shallow Wadi Wala valley, then plunges 600 meters (more than 2,000 feet) into Jordan's miniature Grand Canyon, the Wadi Mujib (the Arnon of the Bible). The road reemerges on the south bank of the Mujib onto the plateau of the ancient Moabite kingdom, passing near the Nabatean temple at el-Qasr and the Roman temple/Byzantine church complex at Rabba. Twenty minutes to the south is the massive Crusader fortress at Kerak, built in 1136 and retaken by the Arab forces of Saladin in 1189. Twenty minutes east of Kerak is the huge Roman legionary fortress at Lejjun.

South of Kerak, the road winds through Mu'ta and Mazar, major Islamic shrines at the site of the first clash between the armies of Islam and Byzantium in 632 AD. The road passes the Roman/Nabatean temple at Dhat Ras, descends through the Wadi Hasa (the biblical Torrent of Zered), past the Nabatean temples of Khirbet Tannur and Khirbet el-Dharih. It then enters the ancient kingdom of Edom, with its excavated capital at Buseira (biblical Bozra). Half an hour to the south is the Crusader fortress at Shobak, built by Baldwin I in 1115 as a key link in the Crusader outposts that guarded the lands between Jerusalem and Aqaba.

The next major stop on the King's Highway is the unique rock-cut Nabataean capital city at Petra, fulcrum of the ancient world's spice and incense routes for 400 years. You can spend days exploring Petra's 800 monuments, along with the nearby 9,000-year-old excavated Stone Age village at Beidha, two more Crusader castles, an Edomite mountain-top village, and the nearby Roman fortress at Udruh.
From Petra, the King's Highway descends gradually past Wadi Rum and its moonscape-like natural wonders, before reaching the warm resort of Aqaba with its Mamluke castle, Islamic-Byzantine towns, and one of the world's oldest known churches.