You might want to check out the bus system. We were shocked at car rental for 10 days and around $500 and the TAX was ANOTHER $250. So be careful with that. There's lots to do. Snoqualmie is terrific, but usually more than 1/2 hour to get there. Unless you go late at night. LOL Seriously, there's lots to do in downtown Seattle, as others have said. There's an art museum, spend 1/2 day at Pike's Place (be sure to see the guys at the fish market there), and YES! do the underground tour. You might want to take a Greyline Bus Tour of the city. There's a Duck Tour, too, or Argosy Tours of the bay. Check out Ballard Locks where the salmon go up the fish ladder. If you go to the Needle, you can eat there (takes an hour, but you get to see all 360 degrees as you eat). Check the price of just going up in the elevator...versus going up and eating and then decide. you'll need reservations to eat there. The Pacific Science Center (where the Needle is) has different displays. Then there's Pioneer Square. If you can afford anything that's at Benaroya Hall (oh, my! The sound there is incredible). There's a bubble gum alley that tourists seem to like, and the waterfront has some kitschy shops. For good fish, try Chinook's at Fisherman's Pier/Wharf. No matter where you eat in Seattle area...you won't be disappointed. Take your passport and take an express ferry to Victoria, BC and have high tea at the Empress Hotel. Some very nice quilt shops in the area and quilt book publishers. Oh, so many choices. The problem is how to choose! Enjoy your trip.