Remains of the best-known Iguanodon species have been found predominantly in Belgium, England, Germany, Spain and France. Remains of similar animals have been found in Tunisia and Mongolia, and distinct species have been found in Utah and South Dakota.
The largest find of Iguanodon remains occurred in 1878 in a coal mine at Bernissart in Belgium. With the encouragement of Alphonse Briart, supervisor of mines at nearby Morlanwelz, Louis Dollo oversaw excavation and reconstructed the skeletons. Some were publicly displayed from 1882; the completed restoration makes an impressive display in the Royal Museum of Natural History in Brussels.