Songdo, officially known as Songdo International Business District, is a smart city built on 600 ha of reclaimed land along Incheon's waterfront, 30 km southwest of Seoul, South Korea. It is connected to Incheon International Airport by a 12.3 km reinforced concrete highway bridge called Incheon Bridge. Along with Yeongjong and Cheongna, it is par…Songdo, officially known as Songdo International Business District, is a smart city built on 600 ha of reclaimed land along Incheon's waterfront, 30 km southwest of Seoul, South Korea. It is connected to Incheon International Airport by a 12.3 km reinforced concrete highway bridge called Incheon Bridge. Along with Yeongjong and Cheongna, it is part of the Incheon Free Economic Zone.