Final answer:
The Kaaba is the holiest location in Islam, located in Mecca, Saudi Arabia. It is a pre-Islamic structure rededicated by Muhammad in the seventh century. It has undergone multiple renovations and today is adorned with a silk curtain covered in calligraphy.
Step-by-step explanation:
The Kaaba, located in Mecca, Saudi Arabia, is the holiest site in Islam and has been an important religious structure long before the advent of Islam. According to historical accounts, it was a sanctuary during pre-Islamic times. Muslim tradition states that Abraham (Ibrahim) and his son Ismail constructed the Kaaba, which originally was a simple, unroofed rectangular structure. Throughout the years, it underwent multiple renovations. The pre-Islamic Kaaba was rebuilt in around 608 CE with higher quality materials. It gained its significance in Islamic tradition when the Prophet Muhammad rededicated the Kaaba in 631-32 CE and cleansed it of idols, re-establishing the monotheism of Abraham.
Over the centuries, particularly under the reign of various caliphs and rulers such as the Abbasids, Mamluks, and Ottomans, the structure and the mosque surrounding the Kaaba were expanded and renovated numerous times. Today, the structure is a cubical building adorned with a silk curtain covered in calligraphy with gold and silver thread, called the kiswa, and features a solid gold door added in 1982. The Kaaba and the surrounding mosque complex is a central part of the Hajj pilgrimage, which every Muslim is encouraged to perform at least once in their lifetime if they are able.