Nickelodeon Universe is an indoor theme park in the center of the mall, formerly known as Knott's Camp Snoopy, Camp Snoopy, and The Park at MOA. The park features roller coasters, among numerous other rides and attractions, and is the largest indoor theme park in the United States. Unlike many indoor amusement parks, Nickelodeon Universe has a great deal of natural foliage in and about the park, and its floor has a wide variance in height - the highest ground level in the park is 15 feet above the lowest. This allows for a far more naturalistic experience than would normally occur in an indoor amusement park.