Today, this historic 30-story tower is now called the Loews Philadelphia Hotel. But when it first opened its doors in the early 1930s, the PSFS building was the country's first International-style skyscraper and touted for its early modernist form and practicality. Designed by George Howe and William Lescaze, the PSFS building is a locals' favorite; it heavily influenced the designs of its upcoming next-door neighbors at the East Market development.

When the Robinson Building was built in 1946, it was a midcentury modern gem of a department store, designed by Victor Gruen, who is often credited for the invention of modern shopping malls. The Robinson’s Department store stood out as being one of the first postwar commercial buildings in Center City, highlighted by its large namesake sign. The building received a historic designation in 2016, which was then rescinded by the License and Inspection department, much to the chagrin of many preservationists, who fear it could now face demolition. Docomomo held a “wake” for the building’s loss earlier last year.

Hill College House at the University of Pennsylvania was designed in 1958 by Eero Saarinen, who at that point had already designed the Gateway Arch in St. Louis, Missouri. It was a women’s-only dorm, highlighted by Saarinen’s incorporation of a drawbridge to the entrance and spiked roof and fencing surrounding the property. Despite its foreboding exterior, the inside of Hill College House features a large, open atrium, much of which will be retained in the ongoing $80 million renovation.

Roy Larson of Harbeson, Hough, Livingston & Larson designed the iconic midcentury saucer in LOVE Park as a “futuristic celebration of postwar Philadelphia optimism.” The center was saved from demolition after the community rallied for its preservation amid the ongoing park renovations. Work and restoration on the saucer began in September 2016. Now plans have been revealed to turn the saucer into a restaurant by late 2019, with 360-degree views of the park and surrounding buildings. Much of the structure will stay the same, but the walls will be replaced with specially engineered glass, that the Parks Department says will allow for better views.

Designed by Geddes, Brecher, Qualls and Cunningham, this Brutalist building was dedicated in 1963 and is known to many as the Roundhouse. It was considered groundbreaking because it was built using an innovative system of pre-cast, pre-stressed concrete. Still, the Roundhouse is one of the many modern buildings in Philly that has a mix of fans and haters alike.

This affordable senior citizen housing building is considered the first major work of Robert Venturi. Built in 1960, the Guild House is also one of Venturi's first expressions of post-modern architecture. Of the Guild House, Venturi once said, "Economy dictated not 'advanced' architectural elements, but 'conventional' ones. We did not resist this."

The front of what's now the Moore College of Art & Design that faces the Benjamin Franklin Parkway is a classic example of International-style architecture. But hiding off the street in a courtyard is a separate structure designed and built in 1964 by the firm Carroll, Grisdale & Van Alen, which architecture critic Inga Saffron has called "the most unsung of Philadelphia's Modernist architects." The awkward-shaped lot caused the architects to design a diamond-truss wall structure at the rear of the 4-story building, which thereby eliminated the need for supporting columns. It was originally the headquarters for the American Society for Testing and Materials.

Built in 1964 and designed by Pietro Belluschi, this 10-story building originally served as the headquarters for the former Rohm and Haas chemical engineering company. It stands out for its use of sunscreens, made of Plexiglass, and its midcentury modern interiors. Last year, there was a nomination to designate the building’s interiors as historic.

Today, the Municipal Services Building is either beloved or reviled by locals. But when it was designed in 1962 by Vincent Kling & Associates and built in 1965, one awards jury touted its ability to provide 500,000 square feet of office space and a gathering space around the significantly different City Hall across the street.