Cardston's old courthouse is a small Romanesque-style sandstone building from the early 1900s, now used as a heritage museum. The original jail cells and court material give it a bit more bite than a standard local-history room, and the stonework is handsome for a town this size.
Pair it with the Card Pioneer Home rather than treating it as a separate destination. Together they fill in the civic side of Cardston's early years: law, settlement, craft, and the everyday work of turning a religious colony into a prairie town.