Unveiling the World's Most Expensive Construction Wonders: Prepare to Be Awestruc
1. Mecca's Great Mosque
Where: Saudi Arabia
Completed Year: Unfinished
Total Cost: $100+ Billion
For nearly two millennia, the Great Mosque in Mecca has undergone continuous renovations, with costs exceeding $100 billion and still rising. Covering ninety-nine acres, this remarkable structure accommodates up to four million worshippers at once, offering expansive indoor and outdoor prayer spaces.
The ongoing upgrades aim to improve accessibility and facilities for the millions of pilgrims visiting annually, especially during Hajj. The vast scale and ambition of this project reflect the mosque's profound importance in the Islamic world and its role as a spiritual center for Muslims worldwide.
These renovations symbolize the enduring significance of faith and community while highlighting the challenges of preserving such a historic site. As enhancements continue, the Great Mosque remains a testament to devotion and evolving religious architecture.

The Mecca Great Mosque
It’s no surprise that Saudi Arabia, an oil-rich nation, invests billions to preserve one of the holiest sites on Earth in a visually stunning and accessible manner. Revered by millions of Muslims, the Great Mosque of Mecca has undergone major restorations since its first significant renovation in 692 AD.
During that initial restoration, the prayer hall's wings were expanded, and wooden columns were replaced with marble, enhancing both beauty and functionality. In 2008, King Abdullah launched a major expansion initiative, followed in 2015 by King Salman’s five large-scale projects to accommodate growing numbers of worshippers.
Saudi Arabia's continuous investment in the Great Mosque reflects its dedication to preserving cultural and religious heritage while adapting to modern needs. This iconic site serves as both a spiritual sanctuary and a testament to architectural excellence and hospitality for pilgrims.