"It's the most precise and complex artefact ever created. The Beholder is installed on the Command Center revealing the entire map. Nothing can escape his prodigious eye."
The Silent Beholder reveals the entire map and watches it for the rest of the game. Unlike other wonders, this is an upgrade of the Command Center and does not require any maintenance, workers, or power once built. New buildings can't be constructed while this wonder is being built. It doesn't need resources to maintain. If Command Center is damaged, you need to repair it before upgrading.
Lookout Towers and Radar Towers can be safely removed after this wonder has been built, as they will be unnecessary.
The map is fully revealed during final wave even without beholder.
While Silent Beholder doesn't produce resources, it provides two significant strategic benefits: it helps identify closed areas and the directions the infected will take during the final attack. See example below:
An example of a map where player could have benefited from building Silent Beholder earlier.
