A tightly bunched archipelago, Palau consists of the high islands of Babeldaob, Koror, Peleliu and Angaur; the low coral atolls of Kayangel and Ngeruangel; and the limestone Rock Islands, of which there are more than 200. Nearly all of the islands in the group sit inside a single barrier reef. The nation's boundaries also encompass six small, isolated islands, collectively called the South-West Islands, which extend some 370 miles (600km) to the southwest, almost as far as Indonesia.

The region's spectacular underwater biodiversity includes over 1500 species of fish and 700 species of coral and anemone. Other noteworthy sightings include giant tridacna clams, sea turtles, manta rays, gray reef sharks, sea snakes, chamber nautiluses and dugongs (manatees). On and near the land, you'll also be impressed with the massive reptiles, including estuarine crocodiles and monitor lizards. In addition, expect to see dozens of species of birds, colonies of fruit bats (the only native land mammals) on the Rock Islands, monkeys on Angaur, a few nonvenomous snakes and small lizards and more insects than you ever thought possible. There are no poisonous land animals on any of the islands.

The Palauan government has set aside a group of its uninhabited Rock Islands - the 70 Islands - as a marine reserve, prohibiting public access so as not to disturb nesting turtles and seabirds. Otherwise, there are no national parks.

In Koror, the average daily high is 87°F (30°C) and the average daily low is 75°F (24°C). Humidity averages a sticky 80%, though it's washed down by 150in (3800mm) of rain annually. Palau's waters are always in the low 80s °F (high 20s °C). Typhoons are uncommon in Palau, which lies outside the typhoon belt, but when they arrive it's usually between June and December.