Does anyone know the historical background and value of the two small stone piers in front of the door?

These two small stone piers are called doorways.

The door is a pair of flat stone piers or drums placed opposite the entrance of the traditional Han building (because the drums are magnificent, people think they can avoid ghosts and admire them). Including Baogu Stone and Jiangjunmen Pillow Stone, in ancient times, different levels of doors were also very strict.

Door stones are generally placed on both sides of the gates of ancient Han traditional buildings to show the decorative art of the ancient gates marking the owner's rank and status. Together with the door pin, threshold, door leaf and door frame, it produces an ancient and elegant overall artistic decoration aesthetic feeling, which is a symbol of auspiciousness, blessing and avoiding evil. And with the building reflect each other, harmonious and unified, play the role of finishing touch, become an indispensable part of traditional residential buildings.