Every year, millions of Muslims come from all around the world to make the Hajj pilgrimage in order to complete one of the five pillars of Islam. This has stayed the same for just over a millennia. However, Mecca has drastically changed over the decades.Mecca’s transformation is fascinating because, in the last 100 years, it has changed more than ever. Here are some images that have been taken illustrating the changes that have occurred over the years to this Holy site.