A military structure designated Pz.W. 728, located near the town of Międzyrzecz in western Poland. The precise historical context, construction date, and function of this site are not confirmed by the provided search results. The region of western Poland, particularly the area around Międzyrzecz, is known for extensive World War II-era German fortifications, including bunkers and underground facilities, as part of the Atlantic Wall and defensive lines.
However, without specific archival or archaeological confirmation for this particular designation, its origins and purpose remain unverified. Current physical condition and accessibility are also unknown.