One of the great things about a vacation in Seattle is the ability to mix a nature experience into the urban vibrations of the city. One of my favorite characters in the Seattle nature scene the Great Blue Heron (the Official City Bird of Seattle, no less).
I never get tired of seeing the Great Blue Herons that Seattle has in abundance. When I see them, I inevitably point and say, "Look, a heron!" For some reason, the beauty and excitement of these birds just never gets old. I always marvel at their grace, their patience, and their lightning speed when it's time to take action.
If you want to see herons, there are a number of places you could go. My favorite (primarily because it's close to home) is the Ballard Locks. There is a colony nearby in the neighborhood of Magnolia, and you will typically see one or more standing at the water's or balancing on a wire stretching over the water below the dam.
The Seattle Audubon Society web site has a great resource if you want to know more about herons in Seattle. There you'll find miscellaneous facts (for example, "The Great Blue Heron can swallow a fish many times wider than its narrow neck"), information on where to find them, and links to research and information about the Great Blue Heron.