Merzougha is roughly a 7-8 hour drive from Fes through the Mid and High Atlas Mountains. It is the best way to see large sand dunes. You arrive and then take a 1-1.5 hour camel ride into the dunes. Many choose to overnight in the dunes with an organized tour. Many options are available from many of the local hotels in and around the area. It is possible to have part of your group stay in a hotel and part of your group spend the night in the dunes. We have arranged and sent many groups to Merzougha and many say they prefer to stay one extra day in the large dunes. You can climb the dunes, snowboard down the dunes. The best time to go is April/May. The summer time gets too hot. Groups find it comfortable to do an overnight in during December and Jan. It is worth mentioning that this is a longer drive from Marrakech and cannot be reached in one day. You can visit small dunes in a city called Zagora which is about a 7 hour drive from Marrakech, yet the dunes there are not even in the same category as the ones in Merzougha.