This is an excerpt from the architecture section of Lonely Planet's Morocco guide.
At the centre of the medina (old city), you’ll find labyrinthine souqs (covered market streets) beneath lofty minarets, twin symbols of the ruling power’s worldly ambitions and higher aspirations. In these ancient medinas you can still see how souqs were divided into zones by trade, so that medieval shoppers would know exactly where to head for pickles or camel saddles. In Morocco, souqs are often covered with palm fronds for shade and shelter, and criss-crossed with smaller streets. Unlike souqs, these smaller streets often do not have names, and are collectively known as qissaria. Most qissariat are through streets, so when (not if) you get lost in them, keep heading onward until you intersect the next souq or buy a carpet, whichever happens first.
Wherever there were once commercial interests worth protecting in Morocco – salt, sugar, gold, slaves – you’ll find a kasbah. These fortified quarters housed the ruling family, its royal guard, and all the necessities for living in case of siege. One of the largest remaining kasbahs is Marrakesh’s 11th-century kasbah, which still houses a royal palace and acres of gardens and abuts Marrakesh’s mellah. Among the most scenic are the red kasbah overlooking all-blue Chefchaouen, and Rabat’s whitewashed seaside kasbah with its elegantly carved gate, the Bab Ouidia. The most famous kasbah is Aït Benhaddou.
Near the palace in Morocco’s imperial cities are grand riads, courtyard mansions where families of royal relatives, advisors and rich merchants whiled away idle hours gossiping in bhous (seating nooks) around arcaded courtyards paved with zellij and filled with songbirds twittering in fruit trees. So many riads have become B&Bs over the past decade that riad has become a synonym for guest house – but technically, an authentic riad has a courtyard garden divided in four parts, with a fountain in the centre. With more than 1,000 authentic riads, including extant examples from the 15th century, Marrakesh is the riad capital of North Africa.
More cultural highlights can be found in the Lonely Planet guide to Morocco