Final answer:
Aurora is the 3rd largest city in Illinois. It is renowned for its historical sites and location along the Fox River, and it is a part of the Chicago metro area.
Step-by-step explanation:
The state whose 3rd largest city is Aurora is Illinois. Aurora is a city located in the northeastern part of the state, and it is known for its historic architecture, the Paramount Theatre, and its location along the Fox River.
While it is the 3rd largest city in Illinois, it is also part of the Chicago metropolitan area, which includes a number of cities and towns sprawling out from the city of Chicago itself.