Maryland Zoo in Baltimore

Nestled in one of the city's most picturesque parks, this zoo is home to more than 2,250 animals. Although the zoo boasts contemporary exhibits where lions, giraffes and elephants roam freely, remnants of the Victorian era remain. Some mammals are housed in large barred cages that were built a century ago. The Maryland wilderness exhibit, where visitors explore a cave populated by timber rattlesnakes and walk under swimming river otters, is very popular, as is the children's barnyard.