This tourist attraction draws about 2,000 visitors a day. Ethel Mars began making fine chocolates in a little candy kitchen around the early 20th century. Her small enterprise evolved to produce not only dozens of varieties of superb boxed chocolates, but some of the world's most famous candies: M&Ms, Milky Way, 3 Musketeers, Snickers, and Mars bars.

Alas, the tour lasts only about 10 minutes and consists entirely of viewing stations with an audiotape explaining the chocolate-baking process. You learn very little. But the place does look like a bakery, rather than a factory, which is nice, as no one wants to see their chocolates handled without love. Even more sadly, you get only one small chocolate as a sample -- delicious, but hardly satisfying. (Surely, this is by design; now overwhelmingly in the mood for sugar, you are more likely to buy some of their expensive chocolate.) Note: Come before 2:30pm, which is when the workers start to pack up and go home.

What's really worth seeing is outside: a lovely and extensive 2 1/2-acre gardendisplaying 350 species of rare and exotic cacti with signs provided for self-guided tours. It's best appreciated in spring, when the cacti are in full bloom. There's a little gazebo in which to sit and enjoy the garden, which would be quite peaceful were it not for the busloads of tourists in the area. Behind the garden, also with a self-guided tour, is Ethel M's "Living Machine," a natural wastewater treatment and recycling plant that consists of aerated tanks, ecological fluid beds, a constructed wetlands, reed beds, and a storage pond.