Every city touts its own beauties, but few cities anywhere can lay claim to the sylvan beauty on the banks of the Schuylkill River that are known as Fairmount Park. The Park (4,180 acres) is the largest landscaped park in the U.S. We can walk, bicycle, rollerblade, or drive along Kelly and West River Drives today and feel ourselves deep in the country. In the depths of the Wissahickon Ravine and at other points in the park, the city's tall buildings are not visible over the treetops, and if it were not for the hum of traffic on the Drives, we could be in the pastoral world that Thomas Eakins painted. It was Eakins who immortalized the scullers on the Schuylkill — some of these paintings such as "The Biglen Brothers Practicing" are exhibited today at the Philadelphia Museum of Art. The "Mount" for which the park was named is the rise on which the museum stands. Fairmount Park was the site of the Centennial Exposition of 1876, and several buildings from that earlier fair still stand, notably Memorial Hall. One of the world's largest municipal parks, Fairmount contains several million trees; the oldest zoo in the U.S.; Boathouse Row; cherry blossoms to rival those along D.C.'s Potomac Basin; Robin Hood Dell, an outdoor venue for soul-filled summer singers; the Mann Music Center, the Philadelphia Orchestra's (and others') summer amphitheater; picnic areas; tennis courts; miles of bicycle paths; bridle paths; an azalea garden; hundreds of statues and monuments; and two dozen or so 18th- and 19th-century buildings, which comprise an unusual historical patrimony.

http://www.fairmountpark.org/ 

Valley Forge National Historical Park is the site where the Continental Army spent the winter of 1777–1778 near Valley Forge, Pennsylvania, during the American Revolutionary War. The National Historical Park preserves the site and interprets the history of the Valley Forge encampment. Originally Valley Forge State Park, it became a national park in 1976. The Park contains historical buildings, recreated encampment structures, memorials, museums, and recreation facilities.The park encompasses 3,500 acres (1,400 ha) and is visited by over 1.2 million people each year. Visitors can see restored historic structures, reconstructed structures such as the iconic log huts, and monuments erected by the states from which the Continental soldiers came. Visitor facilities include a Welcome Center and museum featuring original artifacts, providing a concise introduction to the American Revolution and the Valley Forge encampment. Programs, tours, and activities are available year round. The park also provides 26 miles (42 km) of hiking and biking trails, which are connected to a robust regional trails system.

http://www.nps.gov/ 

When you’re at Longwood Gardens, it’s easy to imagine that you’re at a giant, royal garden in Europe. Stroll along the many paths through acres of exquisitely maintained grounds featuring 11,000 different types of plants. Encounter a new vista at each turn: the Italian Water Garden, Flower Garden Walk, aquatic display gardens and many others. Amble through Peirce’s Woods, eight outdoor “rooms” of distinct woodland habitats. Inside the Conservatory is a lush world of exotic flowers, cacti, bromeliads, ferns and bonsai. Each season brings a different pleasure: spring magnolias and azaleas; summer roses and water lilies; fall foliage and chrysanthemums; and winter camellias, orchids and palms. On land Quaker settler George Peirce purchased from William Penn, Peirce’s grandsons planted an impressive arboretum. The presence of a sawmill on the property prompted industrialist Pierre Samuel du Pont to buy the land in 1906 to save the trees. Christmas is spectacularly celebrated with carillon concerts, poinsettias and thousands of lights; summer evenings are embellished with concerts, illuminated fountain displays and occasional fireworks.

http://www.longwoodgardens.org/