We've run into two unexpected control towers thus far. The first: until arriving in Cheyenne, WY I had never seen a control tower for trains.

Well, there are a lot of trains in Cheyenne that must be kept under control. That much is understandable. But a control tower for houses?

It turns out that Stapleton, CO is a redevelopment of the land once occupied by Denver's old Stapleton International Airport, replaced in 1995 by DIA. The control tower remains as an odd visual reminder of what once was... and of how many houses can fit onto a runway.