Boiling Springs is a census-designated place (CDP) in South Middleton Township, Cumberland County, Pennsylvania, United States, and is part of the Harrisburg metropolitan area. The population was 2,769 at the 2000 census. According to the United States Census Bureau, the CDP has a total area of 2.5 square miles (6.5 km2), of which 2.5 square miles (6.5 km2) is land and 0.40% is water.
This seven-acre body of water was formed by partially damming the brook fed from 30 natural springs, including the "Bubble." Children's Lake is home to many ducks, swans, and geese throughout the year. The lake dates to the 1750s when the dam was used to provide water power for iron production. In the mid-18th century, a grist mill was built by Michael Ege on the southeast shore of the lake, to provide flour and grain for the iron works. This building has been converted into apartments. On the east shore, remaining from the pre-revolutionary iron forge complex, are the original forge and the iron master's mansion with the remnants of its terraced gardens. This 1795 Georgian structure is the most outstanding example of architecture in the Boiling Springs Historic District and of major historical significance as the home of the Ege family. The mansion is presently in a deteriorating condition and is uninhabited. The lake feeds into the Yellow Breeches Creek. A picturesque, natural stone three arch bridge, built in 1854, stands behind the mill, spanning the Yellow Breeches Creek. This limestone trout stream has developed a national reputation for fly fishing. Where Children's Lake runs into the Yellow Breeches, a one-mile stretch of water known as "The Junction" provides quality catch-and-release fishing year round. This is arguably the most intensely fished section of water in Pennsylvania when the White Mayfly hatches. Limestone bedrock streams are rich in minerals, which serve as the basis for the trout's food chain and contribute to healthy growth rates for trout.
Boiling Springs and South Middleton Township, which are near the halfway point of the 2,200-mile trail, were designated Pennsylvania’s first Appalachian Trail Community. In 2010, the Appalachian Trail Conservancy started recognizing towns near the trail that are assets to hikers and the trail. As of 2012, Boiling Springs is one of twenty-three designated Appalachian Trail Communities. The Mid-Atlantic Regional Office of the Appalachian Trail Conservancy is located at 4 East First Street in Boiling Springs, sharing space with the Boiling Springs Appalachian Trail Information Center. As one of only four regional offices along the trail, the staff covers New York, New Jersey, Pennsylvania, Maryland, West Virginia, and Virginia south through Shenandoah National Park (to Rockfish Gap/U.S. 250, near I-64). Several hundred hikers pass through every week during the busy seasons. Hikers often mail themselves packages to pick up at the Boiling Springs Post Office, which is feet from the trail. The Boiling Springs Pool offers hikers a shower for $1, and there are several bed and breakfasts, a nearby campground and even a resident who lets hikers sleep in the backyard. Nearby Allenberry Resort Inn and Playhouse rents rooms to hikers for a reasonable rate.