They dug with bayonets, tin cans flattened into shovels, and burlap sacks to haul out the dirt. Above them, only a few dozen meters away, Bolivian soldiers slept under mosquito netting, unaware that the ground beneath the no-man's-land was being hollowed out beneath their feet. For weeks in the spring of 1933, exhausted Paraguayan troops at Fort Gondra, many sick with malaria and stripped to the waist in the heat, pushed a tunnel under the trenches toward the enemy rear. On the morning of 10 May, with a light drizzle falling, they came up behind the Bolivian lines and the war turned, for a few hours, into something out of a fable.
The Chaco Boreal is a vast, flat scrubland of thorn forest and seasonal swamp, baking and waterless for much of the year. Both Paraguay and Bolivia believed oil lay beneath it, and from 1932 to 1935 they fought one of the bloodiest wars in the history of the Americas to control it. More men died of thirst, dysentery, and snakebite than of bullets. Gondra sat near the heart of the southern front, a Paraguayan outpost ringed by Bolivian trenches dug so close that a thrown stone could reach them. The two armies lay in the dirt and stared at each other for over a month, the soldiers worn down by fever and the relentless pressure of an enemy who would not pull back.
The idea belonged to a corporal, Bernabé Mendoza Duré, who proposed digging beneath the enemy line. His commander, Lieutenant Colonel Rafael Franco, approved it on 28 April 1933. With almost nothing in the way of tools, a special detachment worked in secret, shoring up the roof so it would not collapse and carrying the loosened earth away by hand. On 10 May, the rifle company of Lieutenant Salvador Funes moved through the tunnel while two other companies advanced over open ground. Private Ricardo Dávalos was first into the Bolivian rear. The surprise was total, the confusion among the sleeping defenders complete. But victory carried a price: Lieutenant Pantaleón Aguirre, a veteran of many earlier actions, was killed. A trail near Gondra still bears his name.
The famous tunnel raid set the stage, but the larger Battle of Gondra came two months later, from 11 to 15 July 1933, in the immediate aftermath of the Paraguayan victory at the Second Battle of Nanawa. The Paraguayan 1st Division, known as the Iron Division, pushed through dense woods southwest of the fort and enveloped the Bolivian 4th, the Brave Fourth. The trap was nearly closed. What kept it from snapping shut was a rearguard fought by the Bolivian 34th infantry and the Lanza cavalry regiment, led by Captain Germán Busch, who would later become president of Bolivia. Their stand bought time for the encircled men to slip away northward toward Campo 31, the open field that led on to Alihuatá.
On 15 July, the Bolivians withdrew from the pocket without further harassment, carrying out even their heavy equipment. The Paraguayan advance stalled against a fresh blocking position the Bolivian 3rd Pérez regiment had thrown up at Campo Vía, a dry creek bed six kilometers west of Gondra. The name would matter: five months later, that same patch of scrubland would become the site of one of the most catastrophic encirclements of the entire war. Gondra itself left little behind. There is no monument here, no preserved trench line a visitor can walk. What remains is the memory of men who, lacking everything, dug a road to the enemy through the earth itself, and the quiet roll call of those who did not come back.
The battlefield lies at 23.34°S, 59.91°W, in the Presidente Hayes Department of the Paraguayan Chaco, roughly 200 km northwest of Asunción. From a cruising altitude of 6,000 to 8,000 feet, the terrain reads as endless flat thorn forest broken by pale dry watercourses and occasional clearings, with no relief to speak of. The nearest major fields are Silvio Pettirossi International at Asunción (SGAS) to the southeast and Mariscal Estigarribia (SGME) to the northwest in Boquerón Department, the latter holding the longest runway in Paraguay. Visibility is excellent in the dry season (May to September) but the wet season brings haze and standing water across the scrub.