The Grand Mosque is the largest and oldest mosque in the world and surrounds one of the world's holiest places, the Kaaba. The " Holy Mosque Expansion" Project is the largest expansion of the Grand Mosque in its four-thousand-year history.
At a cost of US$22 billion, the new expansion will comprise new pray-yards, walkways, tunnels and the development of existing service facilities to increase capacity of the mosque to more than 2 million people.