The Arsip Nasional Republik Indonesia, or National Archives of Indonesia (located in South Jakarta), offers some intriguing possibilities for researchers wishing to write transnational histories of the country over a range of time periods. The voluminous materials stretch back to the seventeenth century, and indeed anyone looking for documents or data on the development of the country should really pass through here, though scholars often spend much of their research time in the Netherlands if they have to make a choice. This can be a mistake in some cases: there are real, often undiscovered riches in the Arsip Nasional that make a sustained trip worth the effort. The present article looks at one aspect of these riches—materials usable for writing transnational histories of Indonesia—as a window into this archive. We have divided our discussion into two parts. The first examines some of the sources that can be used for writing transnational Islamic histories of the archipelago, and the second examines documents and collections that can be used for writing about the Chinese diaspora to Indonesia and connections generally between China and the islands. These are only two of the possible approaches to take, but they are two of the main ones. We hope that once informed about these sources, other scholars will make better use of these considerable riches, which shed important light on Indonesian history as a whole.