Indoor playgrounds in Philadelphia
Philadelphia has the oldest answer in America to "where do kids play when it's cold": Smith Memorial Playground & Playhouse in Fairmount Park has been running its free indoor playhouse since 1899, and it's still the first place locals send visiting parents. Around it, the modern scene fills in — Star Park's indoor playground at Franklin Mills, Sky Zone for trampolines, and neighborhood spots like Kids Kastle for the toddler crowd. The free-and-historic option means paid venues here have to earn it, and the good ones do; check hours before you go, because Philly venues run shorter days than the suburbs.