Dongbuk Gongsimdon is located in the northeast of the Hwaseong Fortress. It is a 6.8m-tall, three-story oval observation tower, another architectural wonder of Hwaseong Fortress. A stairway spirals up the interior wall of the tower from the bottom to the top platform. It is also called Soragak (turban-shell shape) because stones were piled up in round shape, enabling people to go up. Soldiers were able to observe enemy movements and to fire weapons.