The Iowa State Capitol sits on a low hill east of the river and is unmissable from almost any downtown vantage. Built between 1871 and 1886 to designs by John C. Cochrane and Alfred H. Piquenard, it is the only state capitol in the country with five domes — one large gilded central dome flanked by four smaller copper ones. The interior is even more elaborate than the exterior leads you to expect: marble staircases, mosaic floors, scagliola columns, and a law library with cast-iron spiral staircases that is one of the most photographed rooms in the building.
Free guided tours run on the hour during the week and cover the chambers, the rotunda, and on most days the dome itself — a worthwhile climb for the close-up view of the inner cupola murals. The grounds hold a scatter of monuments to Iowa regiments and a replica of the Liberty Bell. Bring a coat in winter; the building is gorgeous but the wind off the dome plaza is unforgiving.