Essaouira is an old, small seaside city only 180 km from Marrakech. You can take a Supratours bus there for only 70 dh (about 7€). The bus takes 3 hours to go there, with a coffee/lunch pause. Sometimes the buses are full, so it is not a bad idea to buy your ticket in advance.
Essaouira is picturesque, chill, friendly and beautiful. It all about the sea, cats, seagulls and blue color. Tourists, locals, and expats are living there together in harmony. Remember to try the small local, original restaurants. Or buy fresh fish from the market and go to a restaurant that grills the fish for you for a very cheap price, and makes you the salad too if you bring the ingredients. Take a walk on the beach. Walk in the narrow and colorful streets of the medina. And yeah, I totally could get lost there, even the city is small... A great place to wander for hours with your camera.
I really really loved Essaouira, and I think all who have visited there do.