Then, for nearly a century, the research had been quiet until five years ago when a new generation of students from both China and Germany picked up where Xi left off.

The objects of their study were the very same ones Xi had examined: two tangyang models of Qing Dynasty imperial underground palaces — one (the mausoleum of an empress) held in the Beijing-based Tsinghua University's collection, the other (an emperor's mausoleum, previously misidentified) at the Ethnological Museum of Berlin.

These two models, separated by continents and largely forgotten, became the unlikely bridge connecting young architecture students from the two countries.

In 2021, students from Tsinghua University's School of Architecture and Technical University of Berlin's department of architecture and urban history began working side by side across time zones, languages, and cultural backgrounds. They shared research notes, compared scientific data, and exchanged visits.

The Chinese students brought deep knowledge of Qing Dynasty craftsmanship and cultural heritage conservation, while the German students brought fresh eyes, asking unexpected questions about how these paper models compared to Renaissance architectural models from the West.