Preschool children spend most of their day in the indoor classroom, but it is unknown which learning centers or activity types are associated with physical activity (PA) or if children even use learning centers for their intended purpose (e.g., block play in the block center). The present study aimed to describe activity types in which children participate within classroom locations and to compare location- versus activity type-based approaches to characterizing children’s classroom PA. Preschoolers’ (N=50) classroom location and activity type were video-coded and matched with PA level (measured as accelerometer vector magnitude in counts/s) for one indoor free-play period. Multiple activities occurred within each location (median=6.5), with the predominant activity type accounting for 40.7 (sociodramatic play in group location) to 88.4 (manipulative play in sensory location) percent of time in that location. (author abstract)