Garden of the Gods – FREE
This place should be a National Monument, but there's a reason why it's not. The land was donated to the city with the contractual understanding that it would be designated as a city park and an entrance fee would never be charged. You can drive around the loop and choose to hike as many trails as you wish, if you can find a parking space. It is free, that is true, but if you go to the visitor center, you will be charged to watch their 15-minute film, eat at their café, or buy something from the gift shop. I'm just waiting for them to start charging for parking.