Ottawa, Illinois is proud to be a participant of the Illinois River Road Geocaching! Geocaching (geo-cashing) is a great outdoor recreational activity that’s similar to a scavenger hunt. You search for a hidden object using clues and GPS (global positioning system) coordinates. It’s incredibly fun, and becoming more and more popular every day. Ottawa is one of the six Gateway communities along the Illinois River Road, including the portal communities of Marseilles and Streator. Pick up a log book and guide at the Ottawa Visitors Center.