From the record
“The Ysleta Mission, located in the Ysleta del Sur Pueblo within the municipality of El Paso, Texas, is recognized as the oldest continuously operated parish in the State of Texas. The Ysleta community is also recognized as the oldest in Texas and claims to have the oldest continuously cultivated plot of land in the United States.”
Wikipedia article Ysleta Mission, CC BY-SA 4.0.
One of 56 National Register listings published here for El Paso County · listed in 1972 · category: Building · built in 1680, Spanish Colonial Revival architecture.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service


