The Pythian Castle, formally the Knights of Pythias Lodge Hall, is a distinctive 1904 building in downtown Weiser that mixes Gothic Revival and Romanesque elements in a way that would look overdone in a city but seems perfectly correct in a small Idaho town. Listed on the National Register of Historic Places, it's a reminder that Weiser had genuine ambitions in the early 20th century.
The building is not generally open for tourist visits, but it's worth a look from the street as part of a walk through downtown. The stonework and turret make it the most architecturally eccentric building in town.