El Fronterizo, Tucson

Dirt dug up during construction might always turn up some historic relics, and that's why earth underneath downtown structures is always carefully sifted and scrutinized. When this old adobe building was reconstructed in the 1970s, old handset type was found under the floor. More digging revealed that this was the office of a Spanish-language newspaper founded in 1878 by Carlos Velasco. It is now a National Register site. Access is free.