One Man Spent 18 Years Carving the World's Largest Underground Cathedral by Hand

In the small Spanish town of Mejorada del Campo, a sprawling, unusual cathedral rises from a field. It is 35 meters tall, 4,700 square meters in area, and almost entirely the work of one man — Don Justo Gallego Martínez, a monk who dedicated 60 years of his life to its construction.

Don Justo had no architectural training. He began in 1961, working alone, often 10 hours a day, every day, until he died in 2021 at age 96. The structure has no formal blueprints. He built it largely from imagination, inspired by photographs of St. Peter's Basilica.

The Materials

• Bricks from a local factory's reject pile
• Food cans used as molds for columns
• Bicycle tires repurposed as decorative elements
• Scrap metal from construction sites
• Discarded oil drums
• Salvaged wood beams

The Specs

• Footprint: 4,700 m² — comparable to a small commercial cathedral
• Dome height: 35 m
• Columns: 80+, each hand-built
• Permits: None. The cathedral has never been formally licensed
• Donations: Don Justo refused most donations, preferring to use what he could find

What Happens Next

After Don Justo's death in 2021, the cathedral was handed over to the religious order Mensajeros de la Paz (Messengers of Peace), which is now working to legalize, preserve, and complete the building. It has become a pilgrimage site and is being studied by architects and engineers around the world.

Don Justo once said: "This is an act of faith. I will be working until I die." He kept that promise.