Haridwar is where the Ganga leaves the Himalaya for the plains, and everything in the district turns around that fact: the ghats, the akharas, the ashrams, and the evening fire ceremony that ranks among India's great daily sights.
Har Ki Pauri is the centre of it. The ghat's claim is a footprint of Vishnu, and the Ganga aarti is held at sunrise and again at dusk, when thousands of diyas go out on the current. Arrive at least an hour early for a riverside seat, keep small change for the flower-boat sellers, and treat the crowd itself as part of the experience.
Beyond the main ghat are the two hilltop temples flanking the town, Mansa Devi and Chandi Devi, both reachable by ropeway, along with Daksh Mahadev, the ashram quarter of Kankhal, and the wholesale spice-and-brass lanes of Bara Bazaar. It packs neatly into two days: aarti and ghats first, temples and bazaars next, with Rishikesh only 25 km upstream if the trip stretches.
October to April is the season, since summer is fierce on the plains and the monsoon swells the river off the ghat steps. Haridwar is also the state's great transit hub, and nearly every Garhwal itinerary, Char Dham included, starts within sight of these ghats.