The park opened its first roller coaster in 1923, the Wild Cat, an early Philadelphia Toboggan Company coaster. In 1970, it began a redevelopment plan, which led to new rides, an expansion, and its renaming. The 1970s brought SooperDooperLooper, an early complete-circuit looping roller coaster, as well as a 330-foot-tall (100 m) observation tower, the Kissing Tower. Beginning in the mid-1980s, the park rapidly expanded. Between 1991 and 2008, it added eight roller coasters and the Boardwalk at Hersheypark water park. As of 2016[update], its area covers over 110 acres (45 ha), containing 70 rides and attractions, as well as a zoo called ZooAmerica – North American Wildlife Park. Adjacent is Hershey’s Chocolate World, a visitors’ center that is open to the public and that contains shops, restaurants, and a chocolate factory-themed tour ride.