Seattle is an outdoor lovers paradise ! Just the fact that the ( unofficial ) "symbol" of the Pacific Northwest great outdoors - REI - is located in Seattle downtown, tells how much Seattleites love playing in the great outdoors !
Seattle is one of few cities around US that offers an abundance of outdoor activities in and around its downtown, with bicycling being, perhaps, Seattleites' most favorite one.
Urban trails include shared use paths, bike lanes, signed bike routes, arterials with wide shoulders, and pedestrian pathways. And a great thing about bike lanes/trails, is that they can be used by land paddlers as well.
One of these popular bike trails is a 6 mile loop around Lake Union.