Gurudwara Nanak Piao is situated off Grand Trunk road near the Azadpur Mandi. It is built on the place where the first Sikh Guru, Sri Nanak Dev resided during his visit to Delhi in the year 1505. His Muslim disciple, Mardana accompanied him. As customary to that period, people started flocking the area to take the blessing of the Guru. It is said that usually every one of them used to bring lots of gifts for the Guru but he used to redistribute them among the poor and needy. This place was christened 'Piao' because during his stay in Delhi, guru himself used to serve water to the people visiting him. You can still see the well used by the Guru to serve water. It is well maintained and is fully protected by enclosures.

It is also said that emperor Sikander Lodhi arrested the Guru when he refused to oblige him of something he asked for. The city received high tremors that night and it was said that it was because of the curse of Nanak. The emperor finally agreed to free the guru after he was convinced by some of the Sufi saints that the guru was a real hermit and not an idolater, as he believed. The story has element of truth as this has found place in various Sikh and Islamic chronicles compiled at that time.