More than 1,800 animals ... thing about this zoo? It's free to visit. The easiest (and most affordable) way to reach the Smithsonian's National Zoo – which sits in Woodley Park, a D.C ...

Nine orangutans, ages 5 to 30, are now participating in an ongoing study of animal cognition at the Think Tank at Smithsonian's National Zoological Park. The animals, who live in the Great Ape ...