The annual Hajj pilgrimage officially began in Saudi Arabia as more than 1.5 million Muslims from around the world arrived in Makkah to perform one of Islam’s most important religious obligations centred around the Holy Kaaba, the holiest site in Islam.

As part of the five-day pilgrimage, worshippers gathered at Masjid Al Haram to perform Tawaf, the ritual of circling the Holy Kaaba counterclockwise.

The Holy Kaaba, a cube-shaped structure located at the centre of the Grand Mosque in Makkah, is the direction Muslims face during daily prayers, known as the qibla.

The structure measures around 13 metres in height and has remained the spiritual focal point of Islam for centuries, according to Al Jazeera.

Inside the Holy Kaaba are marble-lined walls and floors, lanterns hanging from the ceiling and three wooden pillars supporting the roof.

A staircase inside leads to the upper section of the structure.

The Holy Kaaba is covered with the Kiswah, a black silk cloth embroidered with Quranic verses using gold and silver thread.

The covering is replaced every year during the Hajj season by a specialised team in Saudi Arabia.

The Kiswah weighs hundreds of kilograms and is produced using natural silk along with gold-plated and silver embroidery.

Saudi authorities estimate its production cost at more than 25 million Saudi riyals.

During Hajj, the lower part of the Kiswah is lifted to protect it due to the large number of pilgrims touching the Holy Kaaba during rituals.