Gurdwara eat free vegetarian food brought in by Sikhs worshiping at the "gurdwara". They may also have a library, nursery, classroom, meeting rooms, a gift shop, and finally a repair shop. A "gurdwara" can be identified from a distance by tall flagpoles bearing the "Nishan Sahib", the Sikh flag. The most well-known "gurdwara" is the Harmandir Sahib (popularly known as The Golden Temple) in Amritsar, Punjab, India, which is the center of power (Akal Takht) of Sikhism. The first "gurdwara" was built in Kartarpur, on the banks of Ravi River in the Punjab region by the first Sikh guru, Guru Nanak
Nishan Sahib Sahib can be seen from far away, signifying the presence of Khalsa in the neighbourhood. It is taken down every Baisakhi (harvest festival, mid-April in the Gregorian calendar), and replaced with a fresh flag, and the flagpole refurbished. During the times of Guru Amar Das the Nishan Sahib was white, to represent peace and simplicity. During the time of Guru Hargobind, however the Nishan Sahib changed into a shade of yellow, known as Basanti. After the creation of Khalsa, Guru Gobind Singh introduced blue flag, which is still the colour of the Nihang flags. The first Sikh flags were plain,