During the late 1870's and early 80's, the Beringer Brothers had tunnels dug into the side of Spring Mountain. This was so the wines could be aged in the perfect conditions provided there. (Temperatures around 58 to 60 Fahrenheit and humidity of 75 – 80%, year-round.) However, the tunnels, chiseled out by hand, were dug at a price. Some Chinese immigrant workers lost their lives when tunnels collapsed before being finished. Those workers who never made it out are said to haunt the tunnels where they were trapped and died.
But the most active location on the property appears to be the original Rhine House Mansion. The staff and public have reported the sound of footsteps when no one is near, and lights turning on and off. A man has been seen walking through walls by employees, after the house has closed for the day.