The company that built the nearby building was an economic powerhouse in Vacaville for five decades. The tilt-up concrete building here was constructed in the 70s as a warehouse for the company's products; now it's the Vacaville Skating Center, with one of the large spaces housing an ice rink, while the other is used for gymnastics and community functions.
The cache is a 4-inch diameter, 1-inch thick plastic box with a few small trade items and a log. I emphasise small... there is no pen or pencil, so bring your own. It is not visible from any angle, and is protected from the elements in a spot that veteran 'cachers will recognize, while newer 'cachers will find easily enough.