For urban children, these rights depend to a large degree on the quality of common space and the built environment. Urban neighbourhoods should ideally provide a secure, welcoming transition to the larger world. They should be places where children can play safely, run errands, walk to school, socialize with friends, watch and learn from the activities of others, and begin to accept and enjoy differences. Too often, however, city neighbourhoods are threatening places, physically and socially. Children play on dangerous thoroughfares, among open sewers and piles of debris, and they take their chances with heavy traffic. They may be confined to homes In areas plagued by social tension and violence, they face chronic anxiety.