Thats my neck of the woods and while its a nice idea (its really just a money racket) and in short not worth the trip, if you have been to the manila zoo, seems thats where they got their inspiration, if you catch my drift.
getting there from the National Highway is straight forward enough, just turn left at the LGU in the middle of Amlan, but the road is not complete and its a little far to be considered a local trip, and even then the trike cant take you all the way (the locals themselves here are hesitant to go there, as its a pretty steep climb to the gate)
so all in all i wont be rushing to get there and I have two young kids