Aquarium of the Pacific - One of the country's largest aquariums, the Aquarium of the Pacific takes several hours to truly appreciate but those with kids can hit the major highlights in less time, if necessary. While you'll enjoy the usual attractions, this aquarium also features some great live shows that kids love, like those that feature sea otters, seals, and other marine mammals. There's also an outdoor play area for running and climbing, perfect for little ones who've spent too much time in a stroller going from tank to tank. (Warning - There's a very enticing fountain for kids to splash in here, so if you don't want disappointed children, bring a change of clothes.)
El Dorado Regional Park and Nature Center - This expansive park has a number of attractions that both parents and kids will enjoy. The Nature Center is the most visited portion of the park and provides "touch tables" where kids can feel animal skins, bugs, and other "natural" things. The nature center also provides puppets so kids can create their own show. In addition, the park boasts hiking trails and a pond with turtles and large fish. A perfect place to go when you've had enough of museums!
Angels Gate Park - If your kids enjoy kite flying, this is one of the best places to indulge in this activity. Always windy, Angels Gate Park provides pretty views of the city and on clear days, you can even see Catalina Island. Aside from kite flying, however, there are a number of other things to see at this park, including the Marine Mammal Care Center, which usually houses up to 50 injured animals, who are being nursed back to health by a loving and knowledgeable staff. (There's no fee to enter but a donation is suggested.) Also at Angels Gate Park is the Fort MacArthur Military Museum, which will appeal more to older kids and adults, who will love the fact that the exhibits are inside the old tunnels and fortifications of an old army battery. (Little ones might be creeped out by the darkness.) The park also has a really good playground and a few miniature train exhibits, courtesy of some local railroad clubs.
Cabrillo Marine Aquarium - If you're children are too young to appreciate really big aquariums, this is the perfect one for them. Small and free - though a donation is suggested - the Cabrillo Marine Aquarium in San Pedro offers several small display tanks and - the "piece de resistance" - a touch tank with irresistible sea life like starfish and colorful urchins. Hardly ever crowded, this tiny gem will take only about an hour or so to visit and the facility is stroller-friendly and easy to navigate.
International Printing Museum - Best suited to kids over six, this museum shows how printing was accomplished before inkjet and laser printers. It's necessary to take a one-hour tour in order to truly appreciate the museum because the tour includes lots of fun demonstrations on old machinery, including a replica of the original Gutenberg Press. Hours are limited so be sure to call before you go.
Los Angeles Maritime Museum - This small San Pedro gem is ideal for kids who are enthralled with ships. There are dozens of models on display, spanning the ages. Other exhibits tout L.A.'s rich maritime history and the city's ties to the sea, including how people make their living on the waters of the Pacific. Plenty of hands-on stuff that kids love is included in many of the exhibits. The staff welcomes kids and is especially cordial to you and them, even if your child is running around the museum, which is located in an old berth. Ramps are provided for those pushing strollers. This is a donation only museum, which makes for a cheap outing.