A public viewing area is a space set aside for members of the public to safely view sites of interest, such as airports, railroads, construction sites or other facilities. Sometimes they are known as visitor centers or interpretive sites.
In locations that have inherent dangers and would not normally be accessible to the public, viewing areas provide a way to satiate the public curiosity without exposing inordinate risk. Many sites contain descriptive signs, viewing pavilions, picnic facilities, toilets, radio receivers and brochures.
Many lock and dam facilities along the various rivers in the US have public viewing areas, including:
These are, by necessity, often temporary in nature. Harkening back to the "knotholes" in fences used by passersby to view the progress of a site, some large projects provide a glimpse into the construction by intentionally placing viewing ports in fences, often geared toward selling space in the final project.
Some stadiums provide locations where the public can view games in progress without entering the stadium or paying for an admission. AT&T Park in San Francisco, California, home of the San Francisco Giants has such an area.