Please click on "original" below to view this image at the largest size. The 20th Street Terminal was only open for one year and look at all the oil and grease spots on the new what was white concrete ramps around the concourses. Concourse 1, occupied by Delta, recently opened this year, a year later than the other concourses, has seriously reduced stains on the ramps around it.

I have labeled various sites around the airport for the benefit of those who are able to remember them and to leave much younger aviation/airport/airline fans with an idea of what was where in 1960.