Across the river from Dubuque, the Wisconsin town of Dickeyville is home to one of the most interesting folk-art environments along the Mississippi: the Dickeyville Grotto (305 W. Main St., 608/568-3119, donation). Started by the priest Matthias Wernerus in 1925 as a memorial to three local boys killed in World War I, the Dickeyville Grotto consists of a series of caves, alcoves, and shrines made of poured concrete almost completely covered in shells, shards, minerals, and gems. Along with the expected Roman Catholic religious themes, parts of the grotto also exhibit a unique vein of patriotic Americana—highlighted by the “Patriotism in Stone” memorial to Christopher Columbus, George Washington, and Abraham Lincoln. With almost no commercialization, the grotto is open 24 hours every day, adjacent to the Holy Ghost Church, a block west of US-61.

Dickeyville can be reached a number of ways. It’s a quick shot north along US-151 from Dubuque, or from Prairie du Chien you can follow scenic Hwy-133 along the east bank of the Mississippi. If it’s summertime and you want an up-close look at the Mississippi, make your way to Cassville, a historic frontier town that holds one of the river’s few surviving car ferries. The ferry (608/725-5180, daily summer, Sat.-Sun. May and Sept.-Oct., $15 per car) has been running since the 1830s.