History isn't always confined to what's in the books. In fact, most times, it's the unwritten history that really paints the most accurate picture of the past. This is most certainly true in Pendleton, Oregon, a historic town cloaked in scandal and secrecy. Hidden away beneath this small town in eastern Oregon, the Pendleton Underground is a network of tunnels that once was home to many secret businesses -- both legal and illegal. It's also a place where Chinese immigrant workers faced egregious persecution and discrimination. It's not pretty, but it's part of Oregon. And thanks to Pendleton Underground Tours, visitors can learn all about the town's untold, underground history.

Beneath the streets of downtown Pendleton, Oregon is a secret district that has been around for more than 100 years.

The Pendleton Underground is a network of tunnels that was once home to many secret businesses, both legal and illegal.

Discovered when potholes started showing up on the streets of downtown Pendleton in the 1980s, the tunnels were built by Chinese immigrants who had been harshly discriminated against by the town’s white population -- to the point that it was unsafe for Chinese people to be out after sunset.

Today, you can take a tour of this abandoned underworld with Pendleton Underground Tours.

The nonprofit started giving tours in 1989, with a mission to educate the community about this untold part of Oregon history.

The Pendleton Underground Tours office is located in Pendleton’s Historic District, on the corner of SW 1st Street and Emigrant Avenue. The buildings that house the tours are all listed on the National Register of Historic Places.

The underground tours provide historical context to the dark side of Pendleton, including bootlegging, prostitution, and gambling.

It also tells the story of the Chinese who lived in eastern Oregon and helped build the state to what it is today.

In order to run businesses and move freely from place to place, hidden tunnels were built beneath the city, forming a secret underground district that became home to numerous illicit activities.

Throughout the Pendleton Underground were saloons, apothecaries, bordellos, a butcher shop, an opium den, and more.

Prostitution was rampant here, too, and the tours don't shy away from these scandalous stories.

The buildings on the tour have all been maintained, true to the original state, allowing visitors to really get a sense of Pendleton as it was a century ago. In addition, historic recreations have been designed to give guests a sense of what was happening in the tunnels during that time.

The story of Pendleton's underground -- the good, the bad, and the ugly -- is an intriguing and essential part of history every Oregonian should know.

Did you know about these underground tours in Oregon -- or the history of Pendleton's red light district? For more information, visit the Pendleton Underground Tours website, or call (541) 276-0730.

If you're looking for another historic tour in Oregon, check out the Astoria Riverfront Trolley.