Rhododendron Species Garden. Federal Way, Washington, US.

"The Rhododendron Species Foundation [was] foundedin 1964 by Pacific Northwest members of the American Rhododendron Society in order to secure the finest authentic forms of Rhododendron species and to develop a comprehensive collection of this plant genus. Because of the destruction of Rhododendron habitat in many areas of the world, conservation has become of primary importance in recent years."  Source: Official Website.