Touristville on the maps (New Seattle p. 60) is just NW of the junction of Hwy 908 (Redmond Way) and Hwy 202 (Woodinville-Redmond Road outside of town, but 164th Avenue in town).
Yahoo Map (zoom to setting 2 or 1 on the map). This is the oldest part of downtown Redmond today.
The Seattle Sourcebook (map p. 169) placed it a little farther north, centered on where the WizKids retail store is located today.
Photo of store.
Touristville is that part of Redmond where tour buses take tourists to see what the tour guides call "The Barrens". It is a civilized place (at least compared to the barrens), located on the edge of the Redmond Barrens. Touristville tours "to the Barrens" operate much like Big Rhino Restaurant is the launching point for tours into "the Ork Underground". It shows the tourists just enough to make them think they've been there and know what its like. What they are really seeing are the slummers from Bellevue who have come to the "Barrens" to experience the thrill and hang out at sleazy clubs. Lonestar does patrol Touristville, but if you go there you should pack your own heat.
A scene in Missing Blood (part of Universal Brotherhood) on page 16 describes touristville as follows: