This study explored children's activity spaces. In 2007, children aged 10–12 years (n=1480) completed a survey and mapping activity, and wore a pedometer for seven days. Their parents completed a survey (n=1314). Over half traveled <25% of their ‘neighborhood’, defined as 800 m and 1600 m network buffers. More local destinations (boys β=−0.022; girls β=−0.013) and parent report of living on a busy road (girls β=−0.43) were associated with smaller activity spaces whereas being independently mobile resulted in larger (girls β=0.28) ones. Traditionally defined neighborhoods may not reflect children's movements. Freedom, fewer local destinations and traffic safety may be important for increasing spatial ranges.