Cannot find Enterprise Search Center when creating a New Site

There could be two reasons for this:

• SharePoint Server Standard Site Collection Features is deactivated.
• Enterprise Search Center is not available under Sub sites can only use the following site templates in Page Layouts and Site Templates under Look and Feel.

Activating SharePoint Server Standard Site Collection Features

• Click Site Actions > Site Settings > Site Collection Administration > Site Collection Features (Can't find Site Collection Administration? Look here)
• Activate - SharePoint Server Standard Site Collection Features

Enterprise Search Center should be visible under Site Action > New Site. If not, keep reading :)

Provide Privilege to use Enterprise Search Center

• Click Site Actions > Site Settings > Look and Feel > Page Layouts and Site Templates and add Enterprise Search Center (All) to the right (as shown below)
• Click Ok.