In the past, there was a large water stream around Buksumun Gate, but during the rainy season, it would often flood. That's why when Hwaseong Fortress was built, both a waterway and Buksumun Gate were constructed. Buksumun refers to the northern gate of Hwaseong Fortress among the two main gates, which was constructed to control the flow of Suwoncheon Stream that cuts through the fortress. Buksumun Gate is also known as Hwahongmun Gate, meaning a shining rainbow.

Hwahongmun Gate has seven Hongyemuns, arched water gates in varying sizes. These arched floodgates were designed to slow down fast streams and were constructed wider and larger as they approached the center. Additionally, Hwahongmun Gate had iron gates to prevent enemies from entering. Furthermore, the stone installed at the bottom of Hwahongmun has been sturdy enough to last until today.