To the west of the ruins perched high on a hilltop, Qala'at ibn Maan is most notable as the prime viewing spot for overlooking the ruins of Palmyra. The castle is said to have been built in the 17th century by Fakhreddine (Fakhr ad-Din al-Maan II), the Lebanese warlord who challenged the Ottomans for control of the Syrian desert. However, it's also possible that some sort of fortifications existed up here well before then.

The castle is surrounded by a moat, and a footbridge allows access to the rooms and various levels within. However, it's not necessary to enter the castle to enjoy the views. The best time to go up is in the late afternoon, with the sun to the west, casting long shadows among the ruins below. To reach the castle on foot is quite a hike with a scramble up a steep zigzagging path to reach the summit. Approaching by car is easier and most of the hotels in town organise sunset trips up to the castle for around S£150.