Islam is the world's second most prolific religion, second only to Christianity. Several sites built in the name of Islam are on the UNESCO World Heritage List. The annual Muslim pilgrimage to Mecca, the Hajj, is one of the largest human migrations. Islam is a traditional religion in most of North Africa, much of the Middle East and parts of Central Asia, South Asia and Indonesia. Since modern times, there are Muslims in most of the world's countries.
As Muslim congregations have had a significant role in most communities where they are present, a traveller will learn much from visiting a local mosque, regardless of belief.
- See also: Holy Land
When entering in a mosque, it is appropriate to dress conservatively and show respect; details vary by place. It is a very good idea to learn a bit about the local rules before visiting a mosque especially if you're a non-Muslim.
According to Islam, several foodstuffs are haram, forbidden, the most known being pork. The taboo is in most cases extended to other pig products, such as gelatin and pig leather.
The Quran condemns alcoholic beverages. In many Muslim-majority countries, they are strongly regulated, if not prohibited.