Children and model train enthusiasts of all ages (and you know who you are) should chug on over to the largest indoor railroad museum on the continent, a Balboa Park tradition dating back to 1935. A labor of love maintained by local railroad clubs, the 27,000-square-foot facility features richly detailed, scale-model displays of four historical Southern Californian rail lines and their landscapes, including a two-level rendering of the famous Tehachapi Loop, the busy and spectacuarly scenic California Historic Landmark. Kids get on board with an interactive toy train train gallery, featuring Lionel trains with whistle sounds and smoke.