The trail system, set to open in the spring of 2014, will include an overhead Big Cats crossing would let them range from their habitat through an enclosed and overhead passageway.
Zoo officials said Monday they expect the new trails to change the way both animals and visitors experience the zoo.
The William Penn Foundation is contributing a $6 million grant to fund the trail system and other initiatives. The foundation says the money reflects its broader investments in the neighborhood, West Fairmount Park.
Mayor Michael Nutter said the new trails will enhance the zoo's national reputation, and offer children and adults a unique learning experience.
"As the Philadelphia Zoo's national reputation rises, it continues to anchor the historic West Fairmount Park neighborhood and serve the citizens of our city by providing a unique learning experience for youth and adults," Nutter said.