The Yexian County Yamen preserves the working architecture of local imperial government: offices, courtyards, kitchens, residential rooms, and prison spaces laid out along a formal axis. It was founded in the early Ming dynasty and is unusually complete for a county-level administrative compound.
That makes it more interesting than its plain name suggests. Temples and city walls are common across Henan; a surviving yamen lets you see the machinery of government at ground level, where magistrates handled tax, law, punishment, and petitions.