Locomotive on the tail end of a northbound Caltrain, pushing into the south portal of tunnel #1, departing 22nd Street station, San Francisco.

Shot with the Nikon D70s and the 18-70mm f/3.5-4.5 zoom at 70mm, ISO 400, f/4.5, shutter 1/400 sec. Contrast, saturation, levels, and highlights adjustments in Aperture.