Amritsar, which can be translated as "Pool of Nectar", the city is the most holy shrine of Sikhism and derives its name from Amrit Sarovar; the holy tank that surrounds the beautiful Golden Temple. In 1573 work began on digging the holy pool. In 1601 the Harmandir Sahib was completed. The Guru Granth Sahib, the holy book of the Sikhs was installed in the holy precincts of the Temple in 1604. The Golden Temple was founded by the fourth Guru of Sikhs, Guru Ramdas and completed by his successor Guru Arjan Dev. During Maharaja Ranjit Singh's reign the lower half of the temple was decorated with marble while the entire upper half was inlaid with copper covered over by gold plate : hence its new name, the Golden Temple. The Temple, with its amazing aura of peace and piety is visited by devotees of all religions. The singing of Gurbani (literally, word of the Guru) forms a backdrop of prayer, and never ceases. The langar provides free food as a "prasad" and rich and poor are found eating here side by side in humble amity.