Just 25 miles east of Seattle, in the foothills of the Cascade Mountains, is Snoqualmie Falls. Winter and spring are the best times to see the thundering 268-ft waterfall; summer brings sun (believe it or not), but less rain and snowmelt.
Although the hiking path down to the base of the falls is currently closed (scheduled to re-open in 2013), the view from the top is well worth the drive out of Seattle...and depending on the wind, you're just as likely to get wet from the spray up there...
(In the Coast Salish language, 'snoqualmie' means 'moon;' the mist from the falls was believed to connect heaven and earth.)
For directions from Seattle: http://www.snoqualmiefalls.com/directions/ For more information about the Lodge/spa located on the cliff just above the waterfall: http://www.salishlodge.com