Experts say little is known about the culture, because its sites have been heavily looted over the years.
"We found several partial pyramids, at least ten," said César Santos Sánchez, chief archaeologist for INC’s Piura division.
"We also found a large adobe platform that we speculate could have been used for burial rituals. But we cannot know without further testing."
The platform, measuring 82 feet (25 meters) by 98 feet (30 meters), was found alongside one of the larger pyramids in the complex.
Another of the larger pyramids contained some artifacts as well as bone fragments from a human skull.
The fact that the skull fragments were found several meters below the surface, indicating a deep grave that took much time to dig, prompted researchers to theorize that the individual buried there had high social status. Santos added that the complex is surrounded by four large hills: Pilán, Vicús, Chanchape, and Tongo.
"We think that because of its geographic location the complex could have been a place of strategic value," Santos said.
The area containing the pyramids is surrounded by a cemetery that has been looted by grave robbers.
"But the complex itself is intact," Santos said.
Who Were the Vicús?
"The Vicús are very interesting but so poorly understood, given that most of what we know about them is through looted ceramic art," said Steve Bourget, an archaeologist at the University of Texas at Austin.
"This could be an important find, because it is one of the few with monumental architecture. But it is too soon to tell."
Experts say the Vicús ceramic style is similar in some respects to that of the Moche, a fact that has spawned research on the relationship between the two cultures.
The Moche civilization flourished in areas south of the Vicús from around A.D. 100 to 750, producing intricately painted pottery as well as gold ornaments, irrigation systems, and monuments.
The two cultures thrived within a relatively short distance of each other—less than that between Los Angeles and San Francisco—experts point out.
"It is possible that the Vicús for part of its history was closely affiliated with the Moche culture," said Joanne Pillsbury, an archaeologist at the Washington, D.C.-based Dumbarton Oaks, a research institute affiliated with Harvard University.
The discovery of the Vicús pyramids comes as perceptions about the Moche have shifted, she added.
"It was once thought that Moche was a single monolithic state, but people don’t think that is true anymore," Pillsbury said.
"It was likely a series of regional or multi-valley kingdoms that shared a broader culture. And Vicús was probably part of that sphere of interaction."