It has come to be known as the eighth wonder of the world. Beneath a suburban house in northern Italy lies a massive underground temple built entirely in secret by a group of non-architects, working around the clock for 15 years. Dug out of the rock without building or excavation plans, it was all overseen by a middle-aged former insurance broker.

In August of 1978, 28-year-old Oberto Airaudi, or "Falco" as he is now known, began building a massive underground temple, known as the Temple of Humankind, in a suburb 30 miles outside of Turin. While for obvious reasons Airaudi chose to keep the project a secret from the government, he did bring on others who he felt understood his vision. Begun as a group of about 24, the Damanhur following now numbers over a thousand. Over a decade and a half, volunteers worked in four-hour shifts slowly excavating the earth and rock. They often hid the sounds of construction by pretending to throw parties.

The Italian police showed up in 1992, 14 years after secret construction was first begun. Having heard rumors of its existence, they demanded to see the temple. When three policemen and a public prosecutor were taken down into the massive and intricately decorated complex they were stunned. The underground temple spreads "over 8,500 cubic metres on five different levels, connected to one another by hundreds of metres of corridors." According to Airaudi, the complex is only ten percent complete.

The structure contains a number of spaces, some with ceilings over 25 feet high. One room is a four-sided pyramid covered in mirrors and topped with a glass dome. The ceiling of the "hall of spheres" is covered entirely in gold leaf. The walls and hallways of the temples are completely covered in murals and sculptures done by the followers. They have a distinctly 1970s new-age feel about them. The temple is said to correspond "to a profound journey inside oneself."

Today the followers of Damanhur live and work in and around the complex, and follow a blend of new-age and pagan rituals with Falco as their spiritual leader. Followers adopt names such as "Sparrow Pinecone," derived from the combined names of animals and plants. According to their website, "the Temples are a great laboratory where art and science, technology and spirituality are united in the research of new roads for the evolution of humanity."

However, not everyone is so enamored with the life at the "Temple of Humanity." Accusations of it being a cult where "people are like zombies, rushing around with vacant stares," are not uncommon.

If you aren’t able to visit in person you can now explore the Temple of Damanhur virtually, with the newly launched Atlas Obscura VR.