ATHENAEUM
Housed in a landmarked Italianate brownstone dating from the mid-1800s and designed by John Notman, the Athenaeum is a research library specializing in architectural history and design. Founded in 1814, it has an American Architecture Collection with close to a million items, and it also contains significant materials on the French in America and on early American travel, exploration, and transportation.
Address: 219 S. 6th St.
Phone: 215/925-2688.

BENJAMIN FRANKLIN BRIDGES
When the bridge opened in 1926, its 1,750-ft main span made it the longest suspension bridge in the world. From dawn to dusk you can jog, walk, or bicycle across; the metal walkway 150 ft over the Delaware River gives you a terrific view of the waterfront.
Address: 5th and Vine St.
Phone: 215/218-3750.

FRANKLIN INSTITUTE SCIENCE MUSEUM.
Founded over 175 years ago to honor Benjamin Franklin, the institute is a science museum that is as clever as its namesake, thanks to an abundance of dazzling hands-on exhibits. You can sit in the cockpit of a T-33 jet trainer, trace the route of a corpuscle through the world's largest artificial heart (15,000 times life size), and ride to nowhere on a 350-ton Baldwin steam locomotive.
Address: 20th St. and Benjamin Franklin Pkwy.
Phone: 215/448-1200.

INDEPENDENCE SEAPORT MUSEUM
Philadelphia's maritime museum houses many nautical artifacts, figureheads, and ship models as well as interactive exhibits that convey just what the Delaware and Schuylkill Rivers have meant to the city's fortunes over the years.
Address: 211 S. Columbus Blvd., at Walnut St.
Phone: 9215/925-543.

PHILADELPHIA MUSEUM OF ART
The museum houses a collection of more than 300,000 works in 200 galleries, including paintings by Van Gogh and Cézanne. The John G. Johnson Collection covers Western art from the Renaissance to the 19th century; the Arensberg and A. E. Gallatin collections contain modern and contemporary works by artists such as Brancusi, Braque, Matisse, and Picasso.
Address: 26th St. and Benjamin Franklin Pkwy.
Phone: 215/763-8100.

BARNES FOUNDATION
It used to be pretty much a secret that one of the world's greatest collections of Impressionist and Postimpressionist art.
Address: 300 Latches La., Merion.
Phone: 610/667-0290.

EASTERN STATE PENITENTIARY HISTORIC SITE
This massive hulk, with 30-ft-high, 12-ft-wide walls and a hub-and-spoke floor plan, was built in 1829 to promote a revolutionary and controversial concept. The reform of prisoners through solitary confinement, in accordance with the Quaker belief that if prisoners had light from Heaven, the word of God and honest work, they would reflect and repent.
Address: 22nd St. and Fairmount Ave.
Phone: 215/236-3300.

INDEPENDENCE NATIONAL HISTORICAL PARK
Independence Hall is just one of the nearly 40 historic buildings contained in this 42-acre enclave. Even if you're not a history buff, we predict a few quivers. Start at the Visitor Center and follow the redbrick road past a dozen stirring sites, which include Independence Hall and the Liberty Bell.
Address: 3rd and Chestnut St.
Phone: 215/597-8974.

MORRIS ARBORETUM.
Begun in 1887 by siblings John and Lydia Morris and bequeathed to the University of Pennsylvania in 1932, this 166-acre arboretum typifies Victorian-era garden and landscape design with its romantic winding paths, a hidden grotto, tropical ferns in a fernery, and natural woodland. An eclectic retreat, the Morris also holds a rose garden, English garden, Japanese garden, and meadows. It has 3,500 trees and shrubs from around the world, including one of the finest collections of Asian plants outside Asia.
Phone: 215/247-5777.