The sundial at the heart of the Tsinghua campus not only marks the passing of the hours, but also seems to point backward toward different eras and lands.
An American might feel more at home than most Chinese near the timekeeper, for it is surrounded by buildings that hark back to age-old American architectural models.
"Tsinghua was originally founded in 1911 by Americans who wanted to create a preparatory school for Chinese aiming to study in the US," says Wang Zhenmin, a professor.
Ironically, if the United States had not engaged in a military clash with China nearly a century ago, the school might never have been built. During the 19th century, Britain, France, Germany, the US, and Japan began carving out areas of influence in China as Beijing's imperial government crumbled.
When Chinese anger at encroachment triggered the antiforeigner Boxer Rebellion a century ago, all the powers sent troops into China to quash the uprising.
Beijing was later required to indemnify the victors, and "the US used its share of reparations to build Tsinghua," says Howard Chan, an American law instructor at the school.
"The American professors who came to start up the Tsinghua Prep School created exact replicas of their favorite buildings from the US," he says.
Circumnavigating the sundial-like hour markers on a larger, architectural clock are clones from such Ivy League schools as Harvard, Princeton, and Yale.
Farther away from the stone timepiece, and dating from further back in time, are the traditional Chinese, fluted-roof structures that were built when the area was part of a magnificent imperial garden and school.
"China's emperors used to send their kids to study here before Tsinghua was founded," says Professor Chan.
The opposite side of the campus is dominated by boxy, Soviet-style buildings set up in the years after China's 1949 revolution.
"During the 1950s, all of China's schools were patterned after the Soviet Union's," says Professor Wang.
At that time, students were "processed" in assembly-line classes and assigned jobs by Communist Party leaders, and were treated like cogs in the state-planned economic machine.
Today, when China's students once again have the freedom to decide where and what to study, "hundreds of Tsinghua undergraduates are opting to finish their education in the United States," says Vivian Ling, an American program director at the school.
"So many students take off for the United States each year that it seems Tsinghua has once again become an American prep school," she adds.