The oldest town in Zapata County also has some of the oldest structures. San Ygnacio, established in 1830, is the last South Texas community to retain a large selection of 19th-century sandstone structures that once dominated architectural styles along the lower Rio Grande. Many of the structures were homes, built of 18-inch thick sandstone blocks and feature the original mesquite and cypress lintels, doors, and fenestrations. Several of San Ygnacio's structures dating back to the early 1800s have received a National Register of Historic Places designation and continue to be restored and cared for.

The Nuestra Senora del Refugio Catholic Church, completed in 1875, revels in the Spanish vernacular style despite suffering past fire damage. The Jesus Trevino Fort Complex, built in the early 1800s, features an unusual sandstone sundial and is operated by the River Pierce Foundation. With so much of early borderland architecture having been lost to the past, we are lucky to have surviving beauties like the historic sandstones of San Ygnacio.

The broader story of San Ygnacio and Zapata County can be enjoyed through the interactive exhibits at the Zapata County Museum of History in nearby Zapata (15 minutes south on U.S. 83). Gain a wider perspective on regional subjects including its architectural roots, trade and transportation, military history, and the vaquero heritage from the Spanish El Camino Real de los Tejas period through the post Civil War cattle drives.