LARGO - A center where school children can go to study life in salt water marshes is to officially open Saturday at the Largo Narrows Nature Park. City officials are to cut the ribbon during a public ceremony at 11 a.m. Following the ceremony, park employees and the Audubon Society will offer tours of the nature center and the park.The park is at 11901 146th St. N, on the east side of the Walsingham Road bridge to the beach. The single-story nature center with teaching areas, laboratories, display areas and storage facilities, was built with a $350,000 grant from the state. It was designed by architects from Ames-Bortles and Associates of Clearwater. The park opened in 1988. It sits on a 34-acre wedge of land and has been left, for the most part, in its natural state. The city and Pinellas County bought the land for the park from Clearwater Beach cartoonist Dean Young in 1985 for $1.8-million. Dennis Mas, in charge of public relations for the Recreation and Parks Department, said the park is open seven days a week from sunup to sundown.