Makkah is the first of the three holiest places in Islam. It is the birthplace of the Prophet Muhammad ﷺ and where this Ummah (nation) began. Despite this, the significance of Makkah predates the Prophet ﷺ. As mentioned in the History of Makkah article, Ibrahim (AS) and Ismail (AS) were the ones who built the Kaaba. Simultaneously, Arab tribes settled around the well of Zamzam (also near the Kaaba in Makkah), creating the first population in Makkah.
Before the Prophet ﷺ, Makkah was a popular tourist attraction for the Arabs. It was the main source of income for the pagans of Makkah and was one of the reasons they didn’t want to turn to Islam/Monotheism. They feared losing their financial gains from the idols that were also part of the attraction. Today, Makkah holds more significance than ever, as it is where Umrah and Hajj are hosted, and historically, it has been one of the hubs of knowledge in the Islamic world.