Name one significant Nebraska landmark.

Chimney Rock is a significant landmark in Nebraska due to its historical and cultural importance. It is a prominent natural rock formation that served as a vital landmark for travelers moving westward in the 19th century, particularly during the westward expansion and the Oregon Trail era. The rock stood as a guide and a source of inspiration for many pioneers and settlers, symbolizing hope and adventure on their journey.

This iconic structure is not only a reminder of the challenges faced by those who traveled through Nebraska but also a reflection of the state's rich history. Its distinctive shape and prominent visibility make it a notable geographic feature, adding to its significance in Nebraska's identity.

While the other options are well-known landmarks, they are associated with regions outside of Nebraska, making Chimney Rock the correct answer in this context.