English: From the source, British Library:

This temple, built by Guru Arjan Dev in the late sixteenth century represents the spiritual centre of the Sikh faith and draws devout pilgrims from all over the world. Here they experience darshan, an auspicious vision of the temple deity, receive religious teachings of the original holy book, the Adi Granth and bathe in the purifying water. The tank has been known as the Amrit Sarovar or Pool of Nectar since the time of Ram Das, the fourth Sikh Guru.

Other information:

The photograph shows pilgrims sitting on the causeway. The ground floor of sanctum is marble walled, the upper floor and dome are copper clad with gold foil cover. This photo from 1870 does not reflect all the changes since then. The Golden temple causeway in 2017 is covered, the courtyard around the pool is now walled and has four main major domed entrances (it was open before and had a Gothic clock tower on one side in late 19th century), inside the courtyard are three remaining Ber trees (there were many more before). There were other major differences.

The scripture is seated inside the square ground floor of the sanctum for about 19 to 20 hours everyday (between about 4 am to about 11pm). For the night, the Guru Granth Sahib is taken to a bedroom inside Akal Takht during the night with an elaborate ceremony, both when it is taken out and when it is returned into the sanctum.