Ala-Kul Lake, Kyrgyzstan

As far as lakes go, Ala-Kul is one of the world's most impressive. Nestled at an altitude of over 11,483 feet (3,500m) inside the Terskey Alatau mountain range in Kyrgyzstan, this stunning pool is one of the globe's natural gems. Enclosed by snow-capped peaks, the glacial lake covers just 0.5 square miles (1.5sq km) but its vibrant cyan waters are enough to entice and delight even the most jaded explorer.