Taq-e Bostan sits at the foot of a cliff where a natural spring emerges, about 5 kilometres from the centre of Kermanshah. The site contains a series of Sassanid rock reliefs and two large barrel-vaulted arches cut directly into the cliff face. The smaller arch dates to the reign of Ardashir II (379–383 AD) and shows a royal investiture scene; the larger arch belongs to Khosrow II (590–628 AD) and is covered in intricate carving — hunting scenes across the walls and ceiling, rows of female musicians, and the magnificent armoured equestrian figure of the king himself in the rear panel.
The scale and detail of the carvings are exceptional, and the spring-fed pool at the base of the cliff adds a tranquil quality to the site. The surrounding park is a popular picnic spot for local families on weekends. The site is open daily; the entrance fee is modest and there is a small museum in the car park area.