In Inner Mongolia's Wuchuan County 武川县, archaeologists have discovered a Northern Wei imperial altar that was probably constructed between 430-490 CE. This is the first time that a Northern Wei imperial altar has been found. The site was discovered in the 1980s, but its excavation only began in 2019. The altar was used by Northern Wei emperors to perform sacrifices to Heaven, or 天. At the site, archaeologists have uncovered the remains of a round building; its interior diameter is 15.5 meters, while its exterior diameter is 32.5 meters. Within the building remains a small amount of sacrificial pottery has been found. Two round pens for holding sacrificial animals have also been identified. The excavating archaeologists believe the site shows the influence of both steppe and Chinese traditions of offering sacrifices.
For more, see the Xinhua article here.