As Indonesia prepares to move its capital to Nusantara, located in Borneo, Chinese investors are spearheading the development of the site. The massive undertaking aims to create a planned, sustainable city to replace Jakarta.

After an hour’s drive through the jungle of Borneo, you reach more jungle. Your rental van from the Balikpapan city airport shakes precariously, navigating a partial bridge washout. A roadside sign admonishes against poaching the endangered sun bears. By hour three you’ve arrived at Indonesia’s new capital, which is due to start taking over from gridlocked, polluted and seaward-sinking Jakarta in 2028. Welcome to Ibu Kota Nusantara, known locally as just Nusantara or IKN. Eventually, if all goes...