Did You Know The Oldest Building In Iowa Is In Dubuque? You've probably driven by it a million times on your way to Eagle Point Park... but did you know the Dubuque Old Log Cabin is believed to be the oldest building in Iowa? Not just the oldest building... it's also believed to be the oldest building west of the Mississippi River. It was built in 1827 and it's original location was 2nd and Locust Streets in Dubuque. (Right down from St. Raphael's Cathedral.) It was built by a trapper named Louis Arrandeaux in a style called 'dogtrot,' which was developed in countries like Sweden, Germany, Finland and Russia. There's a fireplace on each side and the breezeway in the center allowed for good airflow.