In the Northwest of Hanoi toward the Chinese border lies the Hoang Lien Son Range, with Mount Fansipan, the highest peak of Vietnam (3,143m). This range was christened the Tonkinese Alps by the French, who took a liking to the cool climate. Limestone largely comprises this Northwest frontier where dramatic hills rise from the plains. From Hanoi to the Northwest several routes will get you there, the most spectacular via Dien Bien Phu to Sapa. At Lao Cai, close by, you can cross into China and continue by rail to Kunming.