Founded by Frank Oppenheimer, the brother of J. Robert Oppenheimer and himself a physicist, the Exploratorium contains over 650 exhibits that can't be properly described - they have to be experienced.
Almost all are interactive and hands-on. There's the Tactile Dome, where you make your way along a dark maze entirely by feeling the walls made of various textures. There's a small 'experiment' in which you can find out what a tornado is like by feeling it. But far from focusing only on touch, this unusual 'museum' excites all the senses and the mind.
Kids can blow enormous bubbles and find out how they work while having fun. There are dozens of optical illusions and brain teasers. Stand at one end of a room made of an uneven floor and crooked walls and try to judge how close or far away things are.
Create cloud rings and find out why a baseball curves. Have fun with spatulas and eggbeaters while learning about the science of mixing things.
Scream down a huge tube and take a singing 'test', while exploring the science of sound. Sit in the indented seating area on the upper floor far away from your friend. Then speak in a normal voice - and be heard with crystal clarity!
Then leave Earth for a trip to Mars and find out about wing aerodynamics and chemistry. Come try out the 'shadow box' and imagine what it would look and feel like to actually fly.
Gadgets of all kinds teach kids and adults about electricity and energy while providing fun, interactive 'experiments' that entertain as they educate.
The creativity of the designers is endless as you explore San Francisco made of Jello to study the effects of earthquakes. Rack your brain on some of the world's toughest mathematical problems, as you try to see why a ribbon enclosed on itself has only one side.
Located in the most unexpected of buildings - the classical-columned Palace of Fine Arts, Exploratorium is a wonder to behold inside and out. Near the Golden Gate Bridge in Golden Gate Park, the museum is open daily. (http://www.exploratorium.edu)
San Francisco Zoo
Though smaller than some of the more well known zoos, such as those of San Diego or the Bronx, the San Francisco Zoo is well worth a visit. Home to over 1,000 animals of 220 species, there are excellent displays and the 100-acre grounds are cool and easily walked over.
In the Primate Discovery Center you'll find exotic and rare monkeys near several gorillas in Gorilla World. And check out the Lemur Forest, where there are different kinds of these bug-eyed cousins-to-the-monkeys from Madagascar.
Elsewhere, you can see Sumatran tigers and a rare snow leopard up close. There's an even more rare white tiger in the collection.
The zoo recently acquired a couple of Grizzly's from Montana. Come see these fascinating bears and see for yourself some behavior both fierce and gentle.
Head to the Australian Walkabout and visit the wallabies and kangaroos and one or two koalas in Koala Crossing. Then slide over and see Penguin Island where the world's funniest birds groom and play in the 200-foot pool. But don't miss out on the recently born American Bald Eagle. One of the very few born in captivity.
The Zoo is located at Sloat Blvd and 47th Street. For information visit: www.sfzoo.org online.