Fallingwater is the famous summer home designed by American architect Frank Lloyd Wright in 1935 for Pittsburgh retail mogul Edgar J. Kaufmann. Designed by Wright during the height of his creativity, it is considered an architectural masterpiece so important that it recently joined the Parthenon, Taj Mahal, Pyramids of Giza and China’s Great Wall on The Smithsonian’s “bucket list” of 28 places in the world people should visit in their lifetime. The Grand Canyon is the only other site in the United States to make The Smithsonian’s list.

The structure is intimately integrated with Bear Run and the surrounding woods in the remote reaches of Fayette County. In designing its signature terraces that straddle an active waterfall, Wright explained to Kaufmann: “I want you to live with the waterfall, not just look at it.” Features include flooring set with stones from a local quarry to resemble the bedrock of a stream, a protruding boulder from the living room that doubles as a hearth and “vanishing” windows that offer an unobstructed the view of the verdant surroundings. Wright’s accomplishment was voted “the best all-time work of American architecture” by the American Institute of Architects in 1991 and was an inspiration for the Ayn Rand novel, The Fountainhead.

Now owned and managed by the Western Pennsylvania Conservancy, it is open to the public and draws some 120,000 visitors a year. Today, the property includes a childcare center, gift shop and café located in a visitor’s pavilion. The regular tour season runs from mid-March to Thanksgiving weekend. Tickets are available online or by contacting visitor services. Large groups are urged to call for reservations.

Kentuck Knob, one the last of the private homes American architect Frank Lloyd Wright designed, is nestled in the side of Chestnut Ridge, the western-most ridge of the Allegheny Mountains of Pennsylvania. The one-story Kentuck Knob, completed in 1956 as a residence for local ice cream mogul I.N. Hagan, rests on 80 wooded acres near the village of Chalk Hill in Fayette County, four miles south of the Wright masterpiece, Fallingwater.

As he did with Fallingwater, Wright designed Kentuck Knob to be in harmony with the landscape, rather than dominate it. The crescent-shaped house curls around a courtyard, blending with the contours of the landscape, with walls of native fieldstone, woodwork of Tidewater red cypress and a copper roof. The anchor of the design is a hexagonal stone core that rises from the hipped roof where the living and bedroom wings meet. On its southern side, the house reaches beyond the hillside, braced on stone-faced ramparts. Kentuck Knob today is owned by Lord Peter Palumbo of London, England, who added a whimsical sculpture meadow with major pieces by artists such as Andy Goldsworthy and Sir Anthony, as well as pieces of found art, including a section from the Berlin Wall.

The estate also includes a visitors center with a café and gift shop. Grounds are open to the public daily throughout the year. Visit the Kentuck Knob website for information about times and tours. Reservations are required.

Meadowcroft is a 275-acre park museum that includes a major excavation that is yielding stunning evidence of ancient American cultures and a recreated 19th Century village that offers a taste of rural life in southwestern Pennsylvania more than 150 years ago.

The Rockshelter, named a National Historic Landmark in 2005, is an important archeological site that provides rare insight into the lives of the people who inhabited the region – some dating as far back as 20,000 years ago. Visitors are invited to enter the open excavation to discover how these ancient people lived, their tools, weapons and means of survival. The Rockshelter has drawn the attention of several national publications, with the Washington Post reporting that the findings there suggest, “a whole new way of looking at the ancient history of the Americas.”

The Museum of Rural Life allows visitors to mingle with volunteers who pose as residents of a meticulously recreated 19th century village that includes a one-room schoolhouse, general store, barber and blacksmith shops, clapboard church and a classic covered bridge. Visitors can also learn about turn-of-the-century American life by participating in spinning wool, flint knapping, dipping candles and other activities.

Old Economy Village is the final settlement and historic hub of the Harmony Society, a religious sect that emigrated from Germany in the early 1800s under the leadership of separatist Johann George Rapp. The sect dissolved just after the turn of the century and much of its real estate holdings were bought by the American Bridge Company that expanded the town and renamed it Ambridge.

The village today, a National Historic Landmark, consists of six acres of the sect’s original holdings. Here visitors find 17 restored structures from between 1824 and 1830, a museum, one of the earliest gardens in the country and 16,000 artifacts offering unique insight into the daily lives of the pious, inventive and economically successful Harmonists.

Exhibits at the visitors center helps to explain how the Harmonists came settled in western Pennsylvania, lived a simple, devote life, prospered and made marked contributions to the development of Pittsburgh and the region. Walking the cobblestone streets, visitors can explore the village doctor’s office, general store and cabinet, clock and lock shops. In the village print shop is the oldest flatbed printing press in America. And full the range of the Harmonist’s pursuits can be seen in the 1827 Natural History and Fine Arts Museum, where the communal society displayed its collection of paintings and natural science specimens.

The village is typically open to the public from early March through December. Visit the village website for details. Guided tours and workshops are offered and wedding accommodations can be arranged. An admission fee is charged.

The Rachel Carson Homestead is the birthplace and childhood home of ecologist Rachel Carson, whose bestseller, Silent Spring, warned of the health and environmental dangers of pesticides, influenced national and international environmental policies and launched the modern environmental movement. The five-room farmhouse, circa 1870, and its grounds are today a National Historic Landmark managed by the nonprofit Rachel Carson Homestead Association.

The homestead, located near the banks of the Allegheny River, offers guided walking tours of the rudimentary clapboard house where Carson – the family’s only college-educated child – lived between 1900 and 1930, and the rolling woodlands, grape arbor, apple orchard and garden where her environmental awareness was piqued and that today stand as a study in organic tending and native plants. A self-guided Wild Creatures trail provides a quarter-mile nature hike with educational stops and historical information. The site also includes a bookstore and gift shop.

The grounds and gardens are open to the public throughout the year. House tours are by appointment. The Homestead Association also offers environmental education classes, school and outreach programs and online resources related to Carson and her legacy.