You'll get a cool view overlooking the City and Bay. You can also check it off your site seeing list. No need to eat up at the top, unless you want to. At the base are the Pacific Since Center (a kids science museum), the Chihuly glass garden (very cool blown glass display) and the Experience Music Project (cool music museum, with several hands on exhibits). However, for a view of the City with the Space Needle, try Kerry park.
We highly recommend checking out the huge troll hiding under one of the bridges in the Fremont neighborhood. Also nearby are Fremont brewing company, a large Lenin statue and several restaurants and bars.
Best known to the younger crowd for its appearance in 10 Things I Hate About You, Gasworks park is a fun place to lay in the sun or throw a frisbee. It has a great view of the City, and parts of the plant are still there. It is also has one of the best views of the 4th of July fireworks - but you need to get there early to find a stop and be ready for the packed crowd.
Located in the West Seattle Neighborhood, accessible by car or water taxi, this is one of Seattle's beaches. You can lay out on the beach (it may not be what you are expecting, but it does have sand though). There are some cool beach side restaurants and fairly long trail for walking and running. It also have a nice view of the City.
If you want to get in some mountain biking, head to Duthie Hill. We typically rent bikes from Element Cycles in Redmond. https://www.elementcycles.net/ There are several other options for bike rentals though. We hope to go out during the week leading up to the wedding. Let us know if you are around and would like to join
A favorite of Joe's from his first trip to Seattle. Rent kayaks and head out onto the Lake for a day of fun. Since you will be there around the 4th of July, chances are you will have Seaplanes landing and taking off on the Lake next to you!
About 30-45 minutes from the City, with beautiful views of mountains and Rattlesnake Lake. It's about 4 miles round trip, with 1100 feet of elevation gain. It tends to be busy during the summer so it's a good option for a weekday. From Seattle, drive east on I-90 to exit 32 for 436th Avenue SE. Turn right onto 436th Avenue SE, also signed as Cedar Falls Road SE. Proceed about four miles down the road to the Rattlesnake Lake parking lot on the right.
The Ballard locks are awesome. You can cross them and see the Salmon ladder or try to catch a boat going through. Then if you continue two miles down the road, you will hit Golden Gardens Park (8498 Seaview Pl NW, Seattle, WA 98117), which is a beach on Elliot Bay. But before you get to Golden Gardens, stop at Paseo's for a sandwich (6226 Seaview Ave NW, Seattle, WA 98107).