Chefchaouen's 15th-century clay-brown kasbah contains a lovely Andalusian-style Garden, a former prison, the small Center for Research and Andalusian Studies and even smaller art gallery (only open during exhibitions). One of the fortress' 13 spires, the Portuguese Tower, named after the Portuguese prisoners who built it, features plaques tracing Riffian history and provides exquisite views of the medina.