preschool for children (day-care centre) between ages three and six established by Maria Montessori (Montessori, Maria).

Having developed a method for teaching retarded children, Montessori wanted to apply it to those without learning disabilities. In 1906 she was offered rooms in an apartment building in the slum-ridden San Lorenzo district of Rome. This building had been intended as a model residence for poor families but was in disrepair because of vandalism by residents' unattended children. She accepted the offer, named the rooms Casa dei Bambini, and collected toys, building blocks, and games. When the school was opened in 1907, about 50 children attended. With minimal supervision, they found the challenge of building and fitting to be more fun than their previous rampages. A second Casa was opened in San Lorenzo a few months later, and one in Milan in 1908. Switzerland's Italian-speaking canton of Ticino designated its public preschools as children's houses and ordered them to follow Montessori methods. Similar schools were also founded in Vienna and Geneva.

Although many children's houses and other Montessori schools were closed by the Italian Fascist government in 1934 after Montessori objected to a government decree, new schools were opened in 1947 after the end of World War II. Since Montessori's death in 1952, hundreds of preschools based on her model have opened throughout the world.