In 1927, a bathhouse was built on the Northwest edge of the lake which houses the Seattle Public Theater. A public swimming area was also established. In 1930 a lifeguard station was added. On the Northwest bank of the lake, a community center and public swimming area were built in 1929. The community center houses two conference rooms, a gym and a stage. In 1945 tennis courts were added nearby, and in 1955 a pool was added. On the south side of the lake, the Green Lake Aquatic Theater was built in 1950. In the 70's, the stage was dismantled, but the grandstand remains there today. A children's wading pool was built under the Works Progress Administration (at some point) near the bathhouse.
There is a 2.8 mile paved path that circles the lake, and on the south end there is a decently sized putting practice area.
The circle path is great for exercise and gets used for that extensively. The swimming areas are usually crowded on nice days, which is understandable as places public swimming in the Seattle area are somewhat rare. There are a ton of places to stop and hang out, including very open spaces and some that are a little more secluded if you want to get away from people for a little while. Parking usually isn't terrible.
