The Spiro Mounds, about 25 miles north of Poteau on the Arkansas River, are the most important Mississippian-era ceremonial site in the western half of the United States. Between roughly 800 and 1450 AD, the Spiro people built a complex of earthen mounds, traded with cultures from the Great Lakes to the Gulf of Mexico, and produced some of the finest engraved shell art in pre-Columbian North America.
The site today is a quiet 150-acre park with twelve mounds, a small interpretive trail, and a visitor centre with reconstructed grave goods and exhibits. It is not Cahokia in scale, but it is unhurried and almost always empty. Allow an hour for the trail and an hour for the museum. The center is closed Sundays and Mondays.