Which river was the site of Guru Nanak's enlightenment?

The Kali Bein was the river-like rivulet traditionally identified as the site of Guru Nanak’s enlightenment.

According to Sikh tradition, Guru Nanak disappeared while bathing in the Kali Bein near Sultanpur Lodhi and returned after three days with a profound spiritual message. He then proclaimed that there is one God and that humanity should not be divided by religious labels. The experience is closely connected in Sikh memory with the beginning of his public mission.

Gurdwara Sri Ber Sahib stands on the Kali Bein’s bank at Sultanpur Lodhi, where Guru Nanak is said to have meditated beneath a ber tree. The site is therefore an important pilgrimage location, although Sikhism does not generally treat natural bodies of water as holy in the same way that it reveres the sarovars at gurdwaras.

The Kali Bein is sometimes loosely called a river, but it is technically a rivulet. It flows through Punjab and ultimately joins the Beas–Sutlej system near Harike. It was also the focus of a major community-led cleaning effort in the early 2000s.