Baoli Sahib at Goindwal was the first center of Sikhism. It was established by Guru Amar Das. The Hindus went on pilgrimage to Hardwar and Benaras but the Sikhs needed a place of their own.
Understanding this Guru Amar Das purchased the land and personally helped in the construction of the Gurdwara and Baoli (well) with 84 steps leading down to it. Guru Amar Das said that whoever recited the entire Japji Sahib followed by a bath in the baoli on each of the 84 steps with a pure heart would receive spiritual emancipation.
Besides, the Langar System was started by Guru Amar Das at this place only. Even Emperor Akbar took meal in the Langar, before meeting the Guru at Goindwal Sahib.
Moreover, when Guru Arjan Dev, the fifth Master, decided to compile a volume containing the Banis (compositions) of all his predecessor Gurus, he started collecting these compositions from all possible sources. He sent messages all over the country where Guru Nanak had visited and had established Sangats (congregations) to find out if any of his compositions (written or oral) were available. During this search he also sent Bhai Gurdas (a highly regarded Sikh and nephew of Guru Amar Das) to Baba Mohan, the eldest son of Guru Amar Das, to bring four Pothis that were in his possession. These four volumes were known to contain the utterances of the first three Gurus along with those of some of the Bhaktas.
Baba Mohan is said to have refused to part with the Pothis and Bhai Gurdas returned empty handed. Guru Arjan Dev then sent Baba Budha, the senior most Sikh at that time, to convince Baba Mohan regarding the importance of the project but he too failed to achieve the purpose of his visit to Goindwal. At this point Guru Arjan Dev himself walked bare-footed from Amritsar to Goindwal, a distance of over twenty miles, to obtain the Pothis. On hearing of the arrival of Guru Arjan Dev, Baba Mohan shut himself in a room on the second floor of his house and would not see the Guru.
Guru Arjan Dev sat down in the street in front of Mohan's house and started singing a hymn in praise of him (Mohan). The hymn, which is included in Guru Granth Sahib at page 248, is:
"Mohan Tere Ooche Mandir Mehl Apara....".
The melodious voice of Guru Arjan Dev along with the flattering words of the hymn made Mohan change his mind. He brought the Pothis to the Guru who placed them in a palanquin and brought them with great respect to Amritsar. He then used these Pothis as the main source material in the compilation of the Adi Granth.