Due to its colonial history, many of the place names in Morocco have been transliterated from Arabic to French. Hence something like ورززات would be transliterated into French as Ouazazarte. If it were transliterated directly into English it would look like this: Wazazarte – much easier to pronounce!
Generally, a 'ou' in French is pronounced as a 'w' in English. So if you just substitute the 'ou' for 'w', you will find it not quite so impossible to say.
Similarly, where a French person would put a 'y' for let's say, رياض, an English person would write an 'i'. So the word 'riad' would be written as 'riyad' or 'riyadh' in French. If you're wondering what in fact a riad / riyad / riyadh / ryad is, it is generally used in Morocco to describe a city house with an inner courtyard, mostly with a garden. The smaller properties with no garden are generally called a 'dar' Arabic for 'house'.
Riyadh is also the capital city of Saudi Arabia – it's written the same way in Arabic as the French transliteration. I do not know why it has been transliterated as Riyadh in English as logic would dictate it should be written as riad or riyad.
Marrakech itself has different spellings, depending on the language it has been transliterated into. So from French it's Marrakech, from English it's Marrakesh, and from German, a bit of both-- Marrakesch.