Seward Park, located in the neighborhood of the same name, can easily be considered one of the best parks in Seattle. The park contains old-growth forest, lake shoreline and views of Mt. Baker and Mt. Rainier on clear days. And I saw an eagle there during my last visit, so it got me really excited about the place. There are two playgrounds, a lower playground near the park entrance/lake shore and an upper playground in the interior of the park.
Location: 5895 Lake Washington Blvd S
Number of swings: 1 regular, 1 baby seat, 1 baby bucket (lower playground); 4 regular, 2 baby buckets (upper playground).
Ground material: Wood chips at both playgrounds.
Chain length: Medium-long (lower playground); Long (upper playground).
The lower playground is located near the lake shore at the entrance to the park. It's a smaller swingset with only a single regular swing, a baby seat and 2 baby buckets. The baby seat is big enough for an adult to sit in, but it's not quite the same. This part of the park is amazing; there are amazing views of Mt. Rainier and Lake Washington as you swing.
The upper playground has a bigger swing set: 4 regular swings and 2 baby buckets. It's at the top of the hill after you enter the park and go up into the peninsula. It is surrounded by trees and your swinging view is of a grassy clearing and the meandering trail that enters the forested area. The swings are a little low to the ground, but the seats are of the wider variety, giving one a more comfortable swinging experience.
How to get there: Bus route #39 stops at the park entrance.