The Australian Indian Ocean Territories (AIOT or IOT) is an official term used to refer to the two Australian external territories of Christmas Island and the Cocos (Keeling) Islands. The two territories have a common history, both once a part of Singapore, and share a common administrator.
Though the two territories are widely regarded to be in Southeast Asia, both geographically and culturally and even while it's widely regarded that the South Island in the Cocos (Keeling) Islands is the southernmost point of Asia, you'll need an Australian visa to get to the islands and as flights now only arrive from Perth, it has been categorised under Australia for practical purposes.
Dubbed as Australia's Galapagos Islands, Christmas Island is indeed a true wildlife haven. Whilst it's an island that nearly every Australian would have heard of the island for its annual red crab migration, the island also has impressive forests (most notably The Dales), lookouts, scenery, and a perfect spot for snorkelling.
A group of coral atolls and islands that have a true tropical setting far flung out, 2700 km northwest of Perth. The islands are mostly comprised of ethnic Malays who were brought as slaves during the 19th century but yet have a very distinct culture of their own, including their own dialect of Malay that drastically differs from the Malay spoken in Malaysia, Singapore or Brunei. As the islands aren't flooded with tourists, you'll find some uninhabited islands with pristine white beaches with low-lying waters surrounded by palm trees – indeed a true tropical paradise that's fairly accessible.
Whilst the Ashmore and Cartier Islands are geographically in the Timor Sea (which is a branch of the Indian Ocean), it is not officially a part of the Australian Indian Ocean Territories, nor is it even considered such. As visiting the two islands require special permits and a matter of sovereignty dispute between Australia and Indonesia, it is not covered in this article. The same goes with the Heard Island and McDonald Islands, but it's not usually considered to be part of the Indian Ocean in Australia.
There are six settlements in the two territories combined; four in Christmas Island and two in the Cocos (Keeling) Islands. All of them are just tiny towns; with the exception of Flying Fish Cove, they have populations that are no larger than the 500s.
While both Christmas Islands and the Cocos (Keeling) Islands are destinations in their own right, there are many individual places within both territories that are well worth visiting.
As of 2022, the only way to get into the territories by plane is by taking a Virgin Australia flight from Perth. While there used to be flights from destinations like Jakarta, Singapore or Kuala Lumpur, these have been indefinitely suspended but there is still that one-off flight that flies ever so often.
The route is somewhat like a triangular loop. Flights usually depart from Perth on Tuesdays and Fridays first northwest to the Cocos (Keeling) Islands, then heads east-southeast to Christmas Island before finally returning back to Perth.
It might seem like a great adventurous journey from the coast of Indonesia (especially Java) or Western Australia to either one of these islands but it comes with two catches. Firstly, the waters are very rough around both territories and many have died whilst journeying, particularly closer to the coasts of Christmas Island. Secondly, as these islands are popular among refugees illegally trying to migrate to Australia, the navy heavily patrolls the surrounding waters and if you don't have the relevant documents or messed something up, then the consequences will be waiting for you.
However, it's still possible and if this doesn't discourage you, follow the procedures listed on the Cocos Keeling Islands tourism website if you're sailing to the Cocos (Keeling) Islands or the Christmas Island website if you're sailing to Christmas Island. The council websites for Christmas and the Cocos Keeling Islands may also be of some use.
Your only likely option is to head back on your flight to Perth.