It is designed to be one of the most sustainable on the planet. With a solar power station at its heart and wind farms providing energy for it, it aims to be carbon free.
Unsurprisingly, it is also a hub for clean-tech companies.
Sensors are on everything in Songdo - for example, escalators only move when someone is on them.
Offices and schools are also connected to the network.
Every home has a telepresence system built in like a dishwasher. As well as allowing users to control the heating systems and locks, it offers video conferencing and is intended as a way to deliver education, health care and government services.
Computer scientists will also work to find the best way of extracting meaning from the huge amounts of data created by the project.