Seoul Zoo sits within Seoul Grand Park in Gwacheon, just south of the city, and is one of the largest zoos in East Asia. It holds over 3,000 animals from more than 360 species — big cats, bears, giraffes, gorillas, and an extensive bird section among them. The park setting is attractive, with a lake and wooded hills, and on a fine day the grounds are as much a place for a walk as a zoo visit.
Take subway line 4 to Seoul Grand Park station — the zoo entrance is a short walk or a short ride on the park's sky tram. Allow at least half a day. The zoo shares the park with the National Museum of Modern and Contemporary Art (MMCA), which is worth combining into the same trip.