Call it the Zanskar Grand Loop: Leh west to Kargil, south up the Suru, over Penzi La to Padum, valley days among the gompas, then out southeast past Gonbo Rangjon and Shinku La to the Manali-Leh highway. Seven to nine days, two 4,400-metre passes, one tank-sized question of fuel. Acclimatise in Leh for two nights first; the loop never drops low again.
Leg 1: Leh to Kargil, the warm-up
A paved day down the Indus with mandatory pauses: the confluence viewpoint, Lamayuru's moonland and gompa, the Mulbekh rock-cut Buddha. Sleep in Kargil, tank to the brim, draw cash: the next ATM that reliably works is days away.
Leg 2: the Suru valley and Penzi La
The old door earns its legend. The road climbs the Suru under the double 7,000-metre wall of Nun and Kun, past Panikhar's meadows, onto gravel that worsens as the scenery improves. At Penzi La (4,400 m) the Drang-Drung glacier uncoils below the pass like a river someone paused: the loop's first great photograph. Descend the Stod to Padum by evening: a long, glorious ten-to-twelve-hour day, or split it at Rangdum's lonely monastery camp.
Padum has the valley's only pump and its supply has moods. The loop's safe rule: full tank at Kargil, top up whatever Padum offers, and carry a jerrican if your machine drinks. Next certain fuel: Keylong side, after Shinku La. Carry cash for all of it.
Legs 3-4: the valley days
Base in Padum and spend two days the way the valley wants. Morning puja at Karsha, the white staircase across the plain; the gentle drive to Zangla's castle ruin and nunnery; Stongdey's terrace for the whole kingdom in one view. Then the non-negotiable: up the Tsarap to the roadhead by Purne, and the gorge walk to Phugtal, the monastery that grows out of a cave. Overnight in a Purne homestay to catch the monks' dawn horns; day-tripping it is possible but feels like leaving the opera at intermission.
Leg 5: out by the new door
The southern road follows the Tsarap past the turnoffs trekkers once owned, swings beneath Gonbo Rangjon (stop; everyone stops; the god-rock insists), and climbs to Shinku La (~5,090 m) where prayer flags mark the Lahaul border. Descend to Darcha and the Manali-Leh highway: civilisation, tarmac, tea stalls. From here, Manali is a day south, Leh a long day north over more famous passes: your loop, your pick.
Machine, driver, manners
Any healthy SUV or Royal Enfield does the loop in season; clearance matters more than power, and water crossings peak with afternoon snowmelt, so cross passes before noon. Local drivers from Leh know every culvert's biography and cost less than a bent rim. On the road: give monks and yaks the right of way, take none of the mani stones, and accept every offered butter tea; refusing twice is rude, and the third cup is where the stories start.
The loop, assembled
D1-2 Leh, acclimatise · D3 Leh-Kargil · D4 Kargil-Padum via Penzi La (or split at Rangdum) · D5 Karsha + Zangla · D6 Purne, walk to Phugtal, homestay · D7 Purne-Shinku La-Darcha · D8 on to Manali or back to Leh. Season: mid-June to mid-October. Pack: cash, jerrican, sun layers, a headlamp for the generator hours, and patience in pass-sized quantities.