Scale model of the Keck Observatory atop Mauna Kea in Hawaii. This simple 3D print of the observatory captures enough visual cues to make it appear very realistic. This is a first draft; look for the CAD file on Tinkercad.com if you'd like to make a copy to elaborate on (with attribution per the license).

When I had the privilege of visiting the Keck Observatory in 1995, the amazing engineering staff gave me the best tour, and kindly contributed all the plans and information I needed to produce the laser-cut scale model of the twin Keck Telescopes offered by http://SpacecraftKits.com. Here's a 3D print in appreciation.