Galta Ji sits in a rocky gorge in the Aravalli hills east of the city walls — a complex of shrines, pavilions, and sacred water tanks (kunds) built into the cliff face, fed by a natural spring whose water is considered holy. The drive or walk up through the hills is already atmospheric, and arriving at the temple complex to find hundreds of rhesus macaques lounging in the pools and around the shrines is one of those genuinely memorable Jaipur experiences.
The main tank, fed by a spring that emerges from a cow-head sculpture, has been used for ritual bathing for centuries. The complex includes temples to Surya (the sun god), Rama, and several other deities, their interiors painted with murals in vivid but faded colors. Pilgrims come throughout the day; the atmosphere is very different from the ticketed monuments in the city — this is a working religious site with no English signage, no guides for hire, and no particular desire to be a tourist attraction.
Go early in the morning for the best light and fewest crowds, or at dusk for the evening prayers. Dress appropriately (shoulders and knees covered), and watch your belongings around the monkeys — they are practiced thieves.