The blue isn't just one colour. The walls are sky-blue, sea-blue, ink-blue, ice-blue and turquoise. Some streets are pale blue with bright blue doors. Some are deep blue with white edges. People repaint their houses regularly, so the town stays bright.
Nobody knows exactly when or why the painting started. Some say it was to keep mosquitoes away. Some say the colour keeps the houses cool by reflecting the sun. Others say blue is simply a calming colour to come home to. Probably all three are true.
Chefchaouen sits in the Rif Mountains, around 600 metres up. The streets climb steeply, so walking through town is a workout. Cats curl up on doorsteps. Plants in clay pots line the staircases. The air smells of mint tea, fresh bread and goat cheese - which the town is famous for.
Every street looks like a painting, which is why Chefchaouen has become one of the most photographed places in Morocco. Visitors come from all over the world just to walk slowly through it.