This photo shows the wash place just outside the Blue Mosque.
The first thing a person does before entering the mosque is to take off their shoes. This is because they are entering a sacred place. Also, when a Muslim prays at the mosque they put their forehead on the floor.
Muslims who come to the Mosque to pray must perform wudu before doing so.
This is a sacred wash that symbolises spiritual cleansing and purity in readiness for coming before God. When a Muslim performs wudu they wash their hands, mouth, throat, nose, ears, arms up to the elbow and feet.