Pipestone's historic downtown is compact, walkable, and unusually handsome for a town of its size. The best buildings use local Sioux quartzite and jasper, giving Main Street a pink-red masonry character that links the commercial town to the stone country around it.
The Calumet Inn is the obvious visual anchor, a Richardsonian Romanesque building from the late 1880s, but the pleasure is in the whole streetscape rather than a single facade. Pick up walking-tour information from the museum if it is open, then give yourself half an hour to look at stonework, old shopfronts, and the courthouse area.