Wilmington is just south of Midewin National Tallgrass Prairie, which is home to the largest bison herd in the state.

[5] Thomas Cox purchased land near Alden's Island in 1834 and built a sawmill, corn cracker, gristmill, and a carding machine facility all of which were powered by water wheels situated on a mill right off of the Kankakee River which runs through Wilmington.

A mural depicting historic Downtown Wilmington was installed facing the Eagle Hotel in October 2023, in anticipation of the 100th anniversary of the establishment of Route 66 coming up in 2026.

One of Wilmington's most notable geographical features is a large island in the Kankakee River, much of which is occupied by a city park.

This island divides the river into a large channel and a smaller one which was used as a natural mill race during the early years of the city.