Five principal hall foundations occupied the central axis of Bohai Shangjing’s palace city. No. 3 was the northernmost high-platform building in this sequence, and No. 3 and No. 4 formed a single compound. The paired foundations matter to the plan: they belong to one architectural unit within the row, rather than representing two detached halls.
From the journal
Palace Site No. 3 at Bohai Shangjing
A conservation plan locates the high platform on the palace city’s central axis and explains how to read its position.
In the same city · Mudanjiang ↗The northern end of the palace sequence
Five foundations along the central line
The palace precinct around that row was a walled stone enclosure, about 620 by 720 metres, with a water ditch outside it. The heritage description divides the palace city into eastern, central and western zones; the main halls stood in the central zone. Its southern gate had two side openings, while the northern Xuanwu Gate faced the outer city’s north gate across another enclosure. These measurements place Site No. 3 within a carefully bounded inner city, not an isolated platform.