Dr. Luis María Argaña International Airport — Mariscal Estigarribia, Paraguay

ESG is the code for Dr. Luis María Argaña International Airport, serving the remote town of Mariscal Estigarribia in Paraguay's Chaco region near the Bolivian border. The airport has a notable military history, having been built with a runway capable of handling large aircraft, which fueled speculation over the decades about its strategic and defense-related purpose in this sparsely inhabited frontier zone. Civilian use of ESG remains limited given the area's very low population density and challenging Chaco environment. The airport primarily supports occasional domestic flights, cargo, and military operations rather than regular commercial passenger traffic, reflecting the isolated character of Paraguay's western Chaco frontier region.