One of the best walking trails in Juneau curves around the Juneau airport.  There is nothing like having a 737 fly over your head or watching floatplanes come and go.  If you are on an arriving plane, you might find the proximity of the mountains to be too close.  On one flight in this summer, I looked out the window at a mountain that couldn't have been 1000 feet from the wing.  Alaska Airline pilots are the best in the world so there is nothing to worry about.