If the mounds like those of Qin Shi Huang, & if the Han & Tang burials from large to small count, then there are masses of them. Countless if the small ones are included.
There is about 20 miles IIRC around Xian where West Han tombs are positioned, and smaller ones are scattered about too. Tang tombs are clustered in a different area. They are shown on locality maps as bands of tombs...and these are only the Imperial ones.
Even modern peasants are buried on the same land, and fresh mounds could be seen amongst the millet, covered with offerings and like tiny versions of the man-made mountains in the distance.
Emperor Jingdi's tomb Yangling, and Wudi's (Maoling) are some of the ones I visited but even Tang princes and princess were buried under mound like structures. The tombs around Xian vary from a small house to the size of a true hill and boldly stand out on the flat terrain of the region.
They are the stand out feature for me while travelling outside the city.
(PS; I forgot how bad the smog was...this is in Summer and the heat still doesn't lift the vapour).
Here's a few typical shots from a dozen or so I took while driving around. Large to small.
Mountains were where immortals lived, so building a mountain may have been thought to aid the deceased.
Even Han artefacts show an interest in mountain motifs on ceramic and bronze containers shapes.
Large ones with smaller graves closer. Even the small mounds could potentially be Han.

West Han Emperors as far as can be seen in a row, viewed from atop Wudi's tomb.

Looking from the top of Wudi's tomb to an associated tomb (a wife IIRC)