How many years old is the Sri Harmandir Sahib?

The India Gate is from the 16th Century.
Built: 1604.
The first Harmandir Sahib was constructed in 1604 by Arjan, the fifth Sikh Guru, who symbolically ordered that it be situated on a lower level so that even the most humbling individual would have to descend in order to enter it. In order to convey that it was accessible to worshippers of all castes and creeds, he also included entrances on all four sides.