As Indonesia is divided up between so many different islands, there isn’t one main point of entry.
By air: The two main airports are Denpasar Airport on Bali and Jakarta Airport on Java. Other islands also have international airports. Most Asian cities fly to one of them directly, as well as citiesa in Australia.
By land: Indonesia has land borders with Malaysia and Papua New Guinea. A long bus journey connects it to Kuching in Malaysia.
By sea: There are ferry connections between Malaysia and one of Indonesia’s bigger islands, Sumatra. Vanimo in Papua New Guinea also has ferry connections with Jayapura (aka Irian Jaya).
By air: Flying is a very frequently used form of transport within the country. There are airports on Sumatra, Java and Bali as well as some of the other islands. Along with the main airlines which operate, smaller carriers also fly between the islands.
By sea: Boats are also extremely important for getting around due to the number of islands in the country. For some islands they are the only way to get there.