Ladakh is not for the acrophobic. The highest airport in the country is at Leh (3,505m); the Leh polo ground at 3,500m is said to be the highest in the world; the world’s highest observatory at 4,517m is in the village of Hanle. But Ladakh also has the dubious distinction of being the home of the world’s highest battlefield, that of Siachen at 6,300m, which is serviced by the world’s highest helipad at 6,400m. So if you come by air from the plains, you will have to spend some time acclimatizing to the altitude before attempting anything even slightly strenuous. Lack of oxygen in the air can cause breathlessness, lethargy, dizziness, headaches, nausea and insomnia. Take it easy for the first 24 hours, and be sure to drink plenty of water and aim for three to four litres a day. Leh’s water supply is notoriously unsanitary so only drink mineral water. Expect to go to the bathroom a lot. Avoid alcohol, if possible.