Children ages 0-5 and their caregivers. The Emma Treadwell Thacher Nature Center offers many self-guided opportunities for little hands to explore! Dig for fossils in the kinetic sand table, build a beaver dam in the stream table, or roast a pretend marshmallow on the plush campfire with some new friends. The Nature Center is open Tuesday-Sunday from 9:00am to 4:00pm. Meet at the Nature Center. No registration is required.