One of the world's biggest cities is sinking, so they're spending $35 billion to build a new capital from scratch. Take a look at Nusantara.

Construction is underway on Nusantara.Firdaus Wajidi/Anadolu/Getty Images

• Indonesia plans to relocate its capital from Jakarta to the new city of Nusantara.
• The new city will cost $35 billion and won't be finished until 2045.

Jakarta, on the northwest coast of Java at the mouth of the Ciliwung river, is Indonesia's capital and its biggest city.

It's home to some 10.6 million people and about 30 million in the metropolitan area. It's also sinking, with about 40% of the area now below sea level.

The Indonesian government plans to move the capital to Nusantara, a new city being built on the eastern coast of Borneo, about 870 miles north of Jakarta.

It will cost an estimated $35 billion and won't be finished until 2045. About 6,000 government workers are expected to move there in time for the next president's inauguration in October, however.

The decision is not without precedent. Brazil shifted from Rio de Janeiro to Brasilia in 1960, while Abuja replaced Lagos as Nigeria's capital in 1991.

But this is the first time that the climate crisis has played a role in the process. In recent years, rising sea levels have made Jakarta the world's fastest-sinking megacity, which sparked the Indonesian government's decision to move the capital.

Take a closer look at Nusantara.