Humanity always cherishes great works of art that stand the test of time. This June, for example, marks the 50th anniversary of The Beatles’ psychedelic Sgt. Pepper's Lonely Hearts Club Band, and the 20th anniversary of Radiohead’s dystopian Ok Computer. These psychologically satisfying birthdays have generated serious appreciation and nostalgia. Similarly, we also love to praise the longevity of innovative architecture. The AIA bestows an annual “Twenty-five Year Award” to acknowledge projects that have "stood the test of time” and “exemplify design of enduring significance.” But one project a year seems stingy. Below are 15 modern classics which, though not always given the easiest start in life, we’ve come to adore:

+ 14

2017’s AIA Twenty-five Year Award winner is I.M. Pei’s striking steel and glass pyramid. Built to replace the overcrowded traditional entrance of Paris’s Louvre Museum in 1989, the transparent structure marked the museum’s new subterranean egress channel. The project’s early years were marred in controversy as many thought the modernist addition to be inconsistent with the Louvre’s ornate French Renaissance architecture. But, since the project effectively eased the circulation woes as intended, the pyramid worked its way into Parisian hearts.

2. Transamerica Pyramid / William Pereira

What’s now widely considered one of the most handsome brutalist buildings of all time was initially loathed. Midcentury master William Pereira was commissioned in 1969 to design San Francisco’s tallest skyscraper. The 260-meter-tall project was seen as egotistical by much of the city’s residents, who would go on to refer to the skyscraper as “Pereira's Prick.” Fortunately, the name didn’t stick, and the building now anchors one of America’s most distinct skylines. In 2009, the San Francisco Chronicle confessed its adoration for the tower: "an architectural icon of the best sort--one that fits its location and gets better with age."

With a roof sloped at 45 degrees that was intended for solar panels, cantilevering corners, and the first tuned mass damper in the United States, Hugh Stubbins and William LeMessurier’s Citigroup Center (1977) is one of the more bizarre buildings to come out of 1970’s New York City. By placing the tower on stilts, engineers conveniently avoided a church at the corner of the site, and created a small street level plaza in the process. However, the building's unusual features didn't come easily: after its completion in 1977, undergraduate architecture student Diane Hartley calculated that the building could easily collapse under relatively common wind conditions. What followed was a top-secret operation to strengthen the building's connections which was completely unknown to the public until 1995.

Architect Daniel Burnham’s turn-of-the-century masterpiece proved that steel construction was the future of design. When presented with an asymmetrical triangular plot of land in midtown Manhattan, Burnham knew that he couldn’t use traditional masonry construction. Stone’s material strength was so low that the walls on the bottom floors would be thick enough to render the space unusable. Burnham concocted a steel framed design with a nonstructural stone facade. Despite the widespread concern that a steel skyscraper would simply blow over in the wind, the Flatiron Building (1902) emerged a triumph, and has become an icon of the Big Apple.

Bertrand Goldberg’s ultra-efficient utopian-brutalist towers of Marina City on the Chicago riverfront remain one of the highest-density housing projects in the western world. The concrete towers were intended to serve as a “city within a city” and are often credited with spurring a wave of post-war residential high-rise development in American cities. The innovative project was the first in the United States to employ the use of a tower crane and include an open-air spiral parking garage. Chicago rock band Wilco immortalized Marina City through the album artwork of their acclaimed 2002 release Yankee Hotel Foxtrot, which featured the Loop’s "corn cobs" on its cover.

The winner of the AIA’s 1975 Twenty-Five Year Award, Philip Johnson’s Glass House is a marvel of modernist design. Along with Mies van der Rohe’s Farnsworth House, the 1949 residence proved a major boost for the international style as a housing genre. Due to its extensive use of glass and reliance on nearby foliage as privacy, the residence still looks chic.

Louis Kahn’s 1965 Biological research facility is also an AIA Twenty-Five Year Award winner, taking the prize in 1992. Kahn was commissioned to design an "intellectual research retreat" in 1959 by Dr. Jonas Salk himself, the inventor of the polio vaccine. Kahn’s picturesque final design is still a preeminent research facility flanked by the Pacific on one side and UC San Diego on the other.

I.M. Pei’s Bank of China Tower was the first of a slew of 1990s Hong Kong skyscrapers to transform the city. The building’s black and white LED lighting scheme combined with its nifty tetrahedral extrusion logic give the project a unique look, and still stands out, towering over most of the city’s 21st-century buildings.

9. John Hancock Tower / I.M. Pei

Save this picture! © via Wikimedia. Photo by Wikimedia user Dong L. Zou in public domain

I.M. Pei’s Twenty-five Year Awardwinning 1976 Boston skyscraper did not debut smoothy. Due to the unfamiliarity of its unprecedented glass facade, high winds, and questionable installation practices, some of the early windows were blown off of the high-rise and onto surrounding buildings and cars. In the chaos of this failure, temporary wooden panels were tacked onto the structure to fill the gaps, gaining the building the nickname the “plywood palace.” But four decades later, and after a total replacement of the building's glass facade, the project stands as Boston’s tallest building and an incredible milestone in glass curtainwall facades.

Cesar Pelli’s twin tower skyscrapers were the tallest buildings in the world when they were erected in 1996. The daring design featured a skybridge, double stacked elevators, and slender spires. Even though the towers only held the title of world’s tallest for half a decade, they are still the tallest two "twin" buildings ever constructed.

11. Sheats Goldstein Residence / John Lautner

This South-Californian John Lautner design makes the perfect abode for motion picture antagonists: in 1998’s The Big Lebowski, the Beverly Hills Sheats Goldstein house plays the Malibu mansion of a pornography kingpin that goes by the name of Jackie Treehorn. Often considered his most striking design, the Sheats Goldstein residence has since been refurbished with an additional nightclub, office, infinity tennis court, and James Turrell light room. The 1963 residence was recently acquired by the Los Angeles County Museum of Art, which plans to refurbish, document, and give tours of the unique space.

Located on the outskirts of Paris, Le Corbusier’s Villa Savoye was rundown and slated for demolition for much of its existence. Erected in the height of art deco, the 1931 structure stands defiantly as one of the field’s first forays into the international style, and a proof of concept for Le Corbusier’s “five points” architecture manifesto. An extensive series of restorations in 1963 and 1985 returned the building to its original glory. Currently, Villa Savoye stands as one of Lego Architecture’s best selling design kits.

Kenzō Tange’s 1990 skyscraper still stands as one of Tokyo’s most imposing buildings, its intricate footprint resolving into two symmetrical peaks of identical height. The Japanese architect envisioned the project as a balance between modernity and tradition. While the massive building pushed the bounds steel and glass construction, the finished structure was intended to resemble the two divided towers of a Gothic cathedral. The facade patterns were used to mimic screen paneling in typical Japanese residences.