Peninsula Pool was built to fill the need created by the Willamette River bath house closures, which were required due to increasing river pollution. As popular as the pool is with people, it also has a history of being enjoyed by Humboldt penguins. In 1957, when the penguins were scheduled to make their debut at the Washington Park Zoo, the zoo's penguin facilities were not yet finished when the birds arrived from Antarctica. Peninsula Pool was used as a holding area until their own space was ready. In 1998, two ceramic tile murals created by artist George Johanson were installed on the south wall overlooking the pool deck. These colorful murals depict people enjoying the water at the beach and at a pool.