Portland is full of legendary urban freakiness (visit the cacophony society for just a little taste) but I suppose our most well known local urban legend of the type you probably mean are the shanghai tunnels, rumored to be full of unhappy ghosts. There are some pictures here on flickr.
And this from a site that does tours now:
"At one time, this great city that we know today as Portland, Oregon, was a river town whose beginnings we often look upon as being nothing more than a humble Victorian settlement. However, in reality it was considered the most “dangerous port in the world” because of the “Shanghaiing Trade” that existed. Stopping for a drink in such notorious establishments as Erickson’s Saloon, the Snug Harbor Saloon, and the Valhalla Saloon, people became unsuspecting victims who found themselves beneath the streets in tunnels and being carried out to the waterfront and sold for “blood money”.
Portland, Oregon, the Victorian-refined “City of Roses” along the Willamette River, earned the reputation of being the “Shanghai Capital of the World” because of the uncontrolled shanghaiing of unsuspecting men. These men, primarily sailors, loggers, cowboys, sheepherders, those who worked on the river, and others that lived a wanderlust life, and who played just as hard as they worked, found themselves victims of the worst “skullduggery” imaginable. Thousands of them found themselves in the clutches of shanghaiers and crimps who either forcibly grabbed them off the streets, slipped “knockout drops” in saloon, pool hall, and gambling parlor drinks. They were hauled out of opium dens and houses of prostitution, or cleverly dropped through “deadfalls” (trapdoors) that were conveniently situated in a wide array of vice establishments.
Women, in early Portland’s history, had to also be cautious when venturing into certain areas of the city. They were warned not to go to dances and to stay out of restaurants, saloons, and other establishments of the evening, They, too, became victims of this shadowy part of the city’s history, and found themselves being carried or dragged through this infamous “network” of wharfrat-dominated shanghai tunnels, and, unfortunately, sold into “white slavery”. Like a “speck of dust”, most of these women just seemed to vanish and were never heard from again.
The victims were held captive in small brick cells or makeshift wood and tin prisons until they were sold to the sea captains. A sea captain who needed additional men to fill his crew notified the shanghaiiers that he was ready to set sail in the early-morning hours, and would purchase the men for $50 to $55 a head. “Knock-out drops” were then slipped into the confined victim¹s food or water.
Unconscious, they were then taken through a network of tunnels that “snaked” their way under the city all the way to the waterfront. They were placed aboard ships and didn’t awake until many hours later, after they had “crossed the bar” into the Pacific Ocean. It took many of these men as long as two full voyages — that’s six years — to get back to Portland."
