Our church youth group was treated to a special tour of what was at one point the Chinatown of McMinnville. It sits under a few of the store fronts on Third Street. Our host was Matt Worrix who owns the building. When he purchased it he said that he found a few strange things in the basement. Many of the boards had Chinese writing on them. Matt has restored the area to what he imagines it was like when the Chinese community lived down there.
Before they could live there, a huge amount of work was required. They had to hand dig out the entire basement of the building. You can still see the marks where the shovels carved out part of the structure. 
It was especially fun to tour the labyrinthine maze a few days before Halloween. Of course the whole tour I'm thinking, "Man, this would make an amazing wine cellar." But that's just me. The underground dwellings date back to a time when we were exploiting cheap Chinese labor in this country (yeah, way back in the day.) The Chinese labor force was building our infrastructure and cleaning up our messes, but they couldn't legally be seen in public during daylight hours. Thus the need for underground shelter.
There is something really fun about having a youth group tour a spooky underground dwelling and then having the tour guide tell them that there is a human skull in one of the side rooms. It's also fun to see the kids laying down on one of the cots and try out an opium pipe. Very educational. For example did you know that when you are smoking opium you absolutely can not lay down on your back? You might forget to swallow and drown in your own saliva. What great things there are to learn just outside my front door. There are rumours that some pretty amazing parties have taken place down in that basement, but that's just rumours. Several people on the tour mentioned that they'd done a similar tour in Pendleton and that the underground dwelling there is several blocks long.