The Tuscany neighborhood, just west of the Redmond Watershed, has a system of trails that loops around and through the neighborhood streets. The outside loop can make an interesting addition to a ride around the Watershed.
There is no dedicated parking space for users of the Tuscany Trails; if you don't live there or nearby, your best bet is to park at the Watershed and ride through there to the Old Pond trail that comes out at 209th Ave NE & NE 122nd, then follow NE 122nd west until it turns into trail instead of road.
Open
Length: 4.5~ miles; outside loop is about 3.5 miles.
Surface: Dirt, gravel, hogsfuel
Share with: walkers, joggers, bicycles, dogs
Parking for: see the
Redmond Watershed page
The trails are public land owned by King County, and the Tuscany Homeowners Association has taken on maintenance responsibilities.
I didn't find any printable maps of the trails around Tuscany, but they do show on (for example) Google Maps. Use "209th Ave NE & NE 122nd, Redmond, WA" as a search point and look west from there.
Tuscany was originally intended to be an equestrian community, and while the planned stables were never built, the trails weaving around the homes are a fine example of how trails can integrate with a suburban development.