Complex sentence: The most well-known gurdwara is the Harmandir Sahib (popularly known as The Golden Temple) in Amritsar, Punjab, India, which is one of the most important in Sikhism and Sikhs are obliged to come at least once in their lifetimes.
Split into simpler sentences: The most well-known gurdwara is the Harmandir Sahib (popularly known as The Golden Temple) in Amritsar, Punjab, India. This gurdwara is one the most important in Sikhism and Sikh's are obliged to come at least once in their lifetimes.