A dollhouse (or doll house) is a toy home made in miniature. Dollhouses have been mainly for children. Making and collecting them, however, is also a hobby for many adults. In the United States and Canada, the term dollhouse is used. In the United Kingdom, the term doll's house is used. Early dollhouses were seen more than 400 years ago as baby house display cases in Europe. Smaller dollhouses that looked like real houses on the outside appeared in Europe in the 18th century. Early dollhouses were hand-made. After the Industrial Revolution and World War II, doll houses were mass produced. They became more standard and cost less to buy. One famous dollhouse is Queen Mary's dollhouse. It took four years to build. Another is Colleen Moore's dollhouse. It took seven years to build.