McManiacs Vintage and Antique Mall is selling antique stereoscopic cards! The price is $5 for one, and 3 for $10.
What is a stereoscopic card? Well, the stereoscope was the precursor to 3D. The stereoscopic cards would be inserted into the stereoscope … with a slightly different images for the left and right eye. When viewed, you would get the illusion of 3D. The invention dates back to the early 19th century.