If you want to attend a party, or a festival like Burning Man, one of the most fundamental necessities is knowing how to get there. Turns out you aren’t so different from the ancient Paracas people of southern Peru: According to a new study out of UCLA, the Paracas laid down huge lines of rocks in the desert to point the way to trade fairs and festivals along the western coast.

Living around 800 B.C., the Paracas’ lines would have predated the more famous Nazca lines by centuries. Beyond the geoglyphs, the Paracas were also known for building large mounds near their homes along the coast. It was on these mounds that trade fairs would be held, and the lines were used to direct visitors to the sites, which typically weren’t permanent structures.

“If you want people to come to your trade fair, you have to point the way,” said Charles Stanish, the director of the Cotsen Institute of Archaeology at the University of California, Los Angeles. “These lines point straight to the ceremonial mounds on the coast where people could trade.”

Scientists seem relieved to finally have a practical explanation for the otherwise mystic-seeming lines, though Stanish notes that the Paracas used their markings differently than the Nazca people. The Nazca lines, for instance, may have been used to point out sacred sites or mountains as opposed to routes. Still, the creation of highly visible markings in the desert sand is an effective form of advertising, what Stanish calls a “social technology.”

Meant to be seen from above, the lines were likely intended to draw the attention of traders from Peru’s highlands. All told, researchers mapped 71 lines in a 15-square-mile area. They all pointed towards five ceremonial mounds about 12 miles nearer the coast, some of which were aligned in directions that marked the winter solstice in June, a likely festival time. As time passed, competition lead festival holders to draw longer and longer lines to indicate larger, more profitable festivals.