These are graves in the vineyards. To bury the dead, one resident told me that first a vertical shaft is dug, followed by a horizontal one perpendicular to the vertical shaft. The body is placed in the horizontal shaft. I don't know what accounts for the difference in type of graves from the two different Provinces.
I found these elaborate graves among in the extensive vineyards leased by Dynasty Winery in Tianjin Province.
There are dozens of graves on this knoll surrounded by pine trees in Junding Winery's vineyards in Shandong Province. Some were built up with stone, others simply mounds of earth.