Busch Gardens continued to grow, and in 1965, opened the 29-acre (12 ha) Serengeti Plains, which allowed the African wildlife to roam freely. It continued to focus on its tropical landscape, exotic animals, and amusements to draw visitors. Busch Gardens began charging admission as the entertainment became more complex, with extra fees for the thrill rides, such as the roller coasters for which Busch Gardens is now known. Alongside sister waterpark Adventure Island (30-acre (12 ha)), Busch Gardens is the anchor of Tampa's 365-acre (148 ha) amusement multiplex. Currently Busch Gardens competes with other such parks in Florida and charges comparable fees. The park is operated by SeaWorld Entertainment, majority owned by the private equity firm The Blackstone Group. Busch Gardens is currently