Under Construction: Mecca Royal Hotel Clock Tower, Mecca

An aerial view taken November 7, 2011 shows the Abraj Al-Bait Towers (also known as the Mecca Royal Hotel Clock Tower), in the holy city of Mecca during the annual Hajj pilgrimage rituals.

When completed later in 2012, it will be the second-tallest building in the world, at 1,971 feet.

By CBSNews.com senior editor David Morgan

Credit: FAYEZ NURELDINE/AFP/Getty Images