I nominate the Houston Zoo, the state’s most popular, for a most-improved award. In addition to the vast new children’s-zoo area, which opens this month, many new walkways and viewing platforms make it more appealing than ever. The zoo is 78 years old, and many of its exhibits were designed to provide ample separation between watcher and watched; the lushly overgrown cheetah habitat, for example, was so far from the visitors lookout that the cheetah himself was never, uh, spotted. The built-in barriers didn’t stop one imaginative little boy from bloodthirsty speculation: “What if that elephant broke out and stomped all over us? What if that lion jumped over that river and ate our guts?” But some of the zoo’s most popular exhibits are new. Just inside the entrance is the home of a trio of koalas, which endeared themselves to a steady stream of visitors despite being sound asleep; even with their heads tucked under their arms, they were just adorable. The gorilla habitat has long been a favorite stop, as has the Wortham World of Primates, a lavish man-made jungle with multiple viewing platforms that enable visitors to spot lots of species at almost any time of day. Perched high in the branches are dozens of monkeys and apes, variously topknotted, mustachioed, or sideburned; look down low for habitat-sharers such as the babirusa, a double-tusked, warthoggy creature that reassures you about your own God-given looks.

The indoor habitats provide a dramatic break from the heat and humidity; in venerable Houston tradition, they are cooled to the point of frigidity (every reemergence into the steam heat gives zoo-goers a bonus sauna). The splashy Kipp Aquarium also offers the soothing, soporific movement of fish and rays. In the nocturnal-mammal house live the morbidly fascinating vampire bats, perched thirstily, wings a-wriggle, atop petri dishes of fresh cow’s blood; nearby is the ever-popular slow loris, who moves through his personal treetops at a speed of, oh, maybe a yard an hour. And in the reptile and amphibian house I enjoyed reading the Latin names for the animals—Bitis is, fittingly, a genus of adders. I also observed firsthand the objectionable behavior of certain specimens of Homo not-so-sapiens, who tapped on the glass of cages and tanks and tossed coins in the pools and ponds despite multiple signs asking them not to. 1513 N. MacGregor, Houston (713-284-1300; www.houstonzoo.org). Open every day 10 to 6. Adults $2.50, children 3 to 12 50 cents, under 3 free. Train tickets $1.35 (under 2 free). Wheelchair accessible.