The site is located within the international business district of Songdo, surrounded by works by world-renowned architects and architectural firms that seem to compete with one another in terms of originality. Furthermore, due to the nature of the reclaimed land, the requirement for a minimum number of underground floors was a key design constraint that was incorporated into the program and design. The program consists of four elements: the u-city Promotion and Experience Center, u-Square, u-Mall, and the u-Transit Center. The U-City Promotion and Experience Center was a theme with few precedents both domestically and internationally. Even where precedents existed, their interpretation and application often included elements that were somewhat disappointing; therefore, the key challenge was determining how to interpret and apply this concept to the specific context of Songdo. Furthermore, harmoniously integrating the U-Transit Center and the U-City Promotion and Experience Center—which have conflicting characteristics—within a single building was also a difficult task.