A memorial dedicated to the victims of the Columbine High School shootings.

This naturally-sourced hot spring is now home to a clothing-optional resort.

An abandoned sawmill from more than 134 years ago stands testament to the ambition of one man.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.