the subjects of geology, ecology, and history. Classes are designed to meet the Georgia Performance Standards and the North American Association for Environmental Education guidelines. The Antebellum Plantation and Farmyard is an open-air museum composed of 19 historic buildings, built between 1790 and 1875, that have been re-erected on the site to represent a pre-Civil War Georgia plantation. The historic houses have been furnished with an extensive collection of period furniture and decorations. The farm features a petting zoo. A grist mill dates from 1869 and was moved to the park in 1965. A covered bridge dates from 1892 and originally spanned the Oconee River in Athens, Georgia. The park provides daily concerts on a large carillon that originated at the 1964 New York World's Fair. The instrument consists of 732 bell-tone rods, electronically amplified through 60 speakers in a decorative 13-story structure. Broadcast tower The short broadcast tower on the top of the mountain transmits two non-commercial stations: television station WGTV TV 8, and weather radio station KEC80 on 162.55 MHz. FM radio station WABE FM 90.1 was located on this tower from 1984 until 2005, when it was required to relocate to accommodate WGTV's digital conversion. W266BW FM 101.1 now has a permit as well. Atop the tower also sits the W4BOC amateur radio repeater, which operates on a frequency of 146.760 MHz. The tower is also used for the park's Project 25 two-way radio systems. Scenic railroad Stone Mountain trails Walk Up Trail is a trail to the top of Stone Mountain ascending in elevation to a height of . The trail is steep, but spectacular panoramic views and cool winds await hikers at the top. Cherokee Trail is an National Recreation Trail. It loops around the mountain base, with a mile section going up and over the west side of the mountain (crosses Walk Up Trail). It passes primarily through an oak-hickory forest, but views of the lakes, streams, and mountain are common. Nature Garden Trail is a scenic loop trail through a mature oak-hickory forest community, it is excellent for viewing shade-loving native plants. A small garden with interpretive native plant signs is at the entrance to the trail. Songbird Habitat Trails comprise two loop trails each running . The field trail is a birding spot and the woodland trail provides shade and numerous native plants. Dogs are not allowed. Park attractions The park features