Robert Staveley used the success of the Rat Ride to persuade his wife that a 'proper' roller coaster be built. He had liked the idea of having a roller coaster coming down the valley at the top of the park, but was faced with the challenge of getting people to the top of the valley to board the train. His wife suggested that the train be sent out to the top and then returned with the aid of two drops. In 1990, construction began on the world's longest roller coaster, costing £5.2 million and over in length, The Ultimate was opened to the public in 1991.