This stately mausoleum is the final resting place of Mao Zedong, Chairman of the Communist Party of China for three decades until his death in 1976. His embalmed remains lie inside a crystal coffin, despite his wishes to be cremated.

Creating the crystal coffin was no easy task. At the time, the country’s sour relationship with the Soviet Union meant Chinese officials couldn’t tap into any of the Soviet’s well-guarded manufacturing secrets. Instead, the government held a clandestine country-wide competition to create a casket for the Mao, using various code names for the endeavor.

They viewed dozens of submissions before finally settling on the one that holds the mummified communist leader. Each one was put through the ringer as it was tested against variables like temperature, vibration, and its ability to withstand an earthquake.

The building the crystal coffin and its embalmed inhabitant reside in is also impressive, especially considering it was built in only six months. Materials from all across China were used to make it, and 700,000 workers from different provinces, autonomous regions, and nationalities did “symbolic voluntary labor” to get it all finished. Art in and around the hall pays tribute to various revolutionary leaders.