One evening each summer, the Boston Children’s Museum stays open after hours and turns its Fort Point waterfront home into a carnival, with game booths, performances, music, and carnival food for sale beside the landmark Hood Milk Bottle on Congress Street.

The draw, beyond games and the prizes every kid walks away with, is the museum itself at a fraction of its usual crowding — this is a limited-capacity ticketed event, so exhibits that normally have lines are easy to wander. It’s pitched at kids from preschool age on up, and the early-evening timing means little ones get the full carnival treatment and still make bedtime. Buy tickets ahead; the museum caps attendance and the night does sell through.