In the Indian Ocean, a few hundred kilometers south of the Indonesian island of Java, lies Christmas Island (not to be confused with Christmas (Kirimati) Island in the Pacific, which is part of Kiribati). It belongs to Australia, has an area of only 135 square kilometers, and a population of around 1500 people of mostly Chinese, European and Malaysian origin.
The island is a rather flat limestone plateau with steep cliffs rising up from the ocean all along the coast. Highest point is Murray Hill (361 m). Most of the island is covered in tropical rainforest, a large part of which is now the Christmas Island National Park. You can do different day-hikes on marked trails through the rainforest and near the coast, and spot some wonderful animals like the notorious red crabs, and a variety of seabird species.