For a dose of 12th-century healthcare, walk into the Nur al-Din Bimaristan, an early hospital. Built by Sultan Nur al-Din in 1154, this was one of the most advanced hospitals of the medieval world, where doctors treated everything from broken bones to "melancholy" using a revolutionary cocktail of herbal medicine and the soothing sounds of running water. The building is a masterpiece of early Islamic architecture, featuring an ornate portal crowned by a mad little dome and a peaceful central courtyard. The modest Museum of Arab Medicine and Science is housed in the four corner rooms, with antique surgical instruments and exhibits on pharmacy and astronomy. A fascinating, tranquil spot in the heart of the city.