A batch of 4,722 pilgrims left Jammu on Friday to perform the Amarnath Yatra as 50,483 devotees completed 'darshan' at the cave shrine till Thursday.While 2,147 pilgrims left the Bhagwati Nagar Yatri Niwas in an escorted convoy for the Baltal base camp, 2,575 proceeded to Pahalgam, police said.Pilgrims taking the 14-km long Baltal trek return back after darshan on the same day while those using the 45-km traditional Pahalgam trek take four days to reach the shrine. Helicopter services are available at both camps.Since July 1, a total of 50,483 pilgrims have had darshan inside the Himalayan shrine situated at 3,888 metres. It houses an ice stalagmite structure that symbolises mythical powers of Lord Shiva, according to devotees.This year's 45-day long annual Yatra will conclude on August 15 coinciding with the Shravan Purnima festival. Historically, the Cave shrine was discovered in 1850 by a Muslim shepherd named Buta Malik.Folklore says a Sufi saint gave the shepherd a bag full of charcoal which tu rned out to be gold. Symbolically, the lore has proved true. Till 2000, Malik's descendants received a portion of the offerings for over 150 years.