The "Nasties" are routes in Forest Park, Portland. Description from https://sites.google.com/site/runs4cache/: "Whereas Wildwood Trail is relatively flat and easy to follow, the "Nasties" are not. They were designed by a mysterious Portland trail runner for hilly off-season training while the volcanoes and high trails of the northwest are under snow and ice. It's believed he also has an intention to increase the suffering in the world."
There are four primary Nasty routes (North, South, Alphabet, and Flaming) and one very popular, commonly run variation (Skyline Nasty, a variation on North Nasty).
North Nasty is a popular 11.5 mile loop, with 2900' of elevation gain, in Forest Park, Portlland. It starts at the Leif Erikson trailhead at Germantown road. Cross Germantown, go down Firelane 9, through the neighborhood above Hwy 30, connect to Linnton trail and head up. Continue up FL 10, through the Newton parking lot and down until it hits BPA road. Climb BPA, head down FL 12, and up FL 15 until it hits Skyline road. Take a left on Skyline road and another left onto BPA road. Go down BPA and turn right on Wildwood trail. Take Wildwood all the way back to 10, go left or down Firelane 10, and descent to Firelane 10a and head back to the start. North Nasty has a Strava segment, but note that the Segment doesn't quite close the loop, which it should. Besides a single lap, an FKT has been reported for 9 laps (just over 100 miles) of North Nasty.
The "Tour de Nasty" is all five Forest Park Nasty routes in a single push (drive/transportation time between trailheads included in overall time). Stats come out to about 67.5 miles and 13,500+ feet of gain.