Tarn Taran Sahib is a major Sikh pilgrimage site south of Amritsar, founded in the time of Guru Arjan. Its great sarovar is the first thing you notice: a broad sacred pool that gives the complex a spacious, reflective character very different from the tighter urban setting of the Golden Temple.
It is not a substitute for Harmandir Sahib, but it makes a worthwhile half-day excursion if you are interested in Sikh history or want to see a quieter devotional landscape. Dress modestly, cover your head, remove shoes before entering, and allow time simply to walk the marble edge of the water.