Chefchaouen's Kasbah was built back in the 18th century by the legendary ruler, Moulay Ismail.

It's a fairly straightforward architectural structure, surrounded by rich vegetation both inside and outside.
For anyone interested the history of Morocco, Africa, the Kasbah is an absolute must see. This is where legendary local chief Abdu l-Karim was eventually imprisoned in 1926 by Spanish troops. It was only with the help of the French that they finally managed to overthrow him. After the fall of Abdu l-Karim, Spain took control over northern Morocco for the next 30 years.
Because of his popularity with the people of north Morocco, he managed to escape execution. In fact, he didn't die till 37 years later in Cairo, Egypt.