As a result, there has been extensive sagging in some beams, so, beginning in September 2010, a full dismantling, repair and reassembling of the gate's roof is being undertaken. Missing Structures Four structures of the original Hwaseong Fortress were not reconstructed but are known from the Uigwe. The first two of these were the South-East Gate Guard Platform (남동적대) and the South-West Gate Guard Platform (남서적대), originally located at both sides of the South Gate. The South Secret Gate (남암문) allowed sallies out of the fortress. The Domgnam Gongsimdon, or the South Observation Tower (남공심돈), like that which stands by Hwaseomun, was an observation tower beside the Suwoncheon. Namsumun (남수문) Extending across the Suwoncheon at the southern part of the fortress is Namsumun (남수문), the South Floodgate. Located a little over a kilometer downstream from its sister, Hwahongmun, the gate is 29.4m long, 5.9m wide and 9.3m high. Construction of the original began on February 28, 1794, was interrupted, then continued in November 1795, and ultimately was completed on March 25, 1796, though the gates basic structure was completed as early as January 16 and came into operation at that time. The bridge features nine arches for the water to flow underneath, two more than Hwahongmun because of the increase in water flow. This particular area was considered a weak point in the fortress' defenses, and thus a large brick structure overlooking the stream was built above the bridge. A feature unique to Namsumun, this defensive structure comprises a whole two-thirds of the gate's total height above the arches, with the bridge accounting for the remaining one-third. Notably, Hwahongmun does not have a similar structure and is instead guarded by lower stone walls and a wooden gatehouse. In 1846, the original Namsumun was swept away in a major flood. It was soon restored but washed away again by a flood in 1922, during the Japanese occupation. During the general restoration of Hwaseong Fortress in 1975, no consensus was obtained on how to rebuild the gate, and the area was left reserved for restoration at a later time. The issue arose again during the rehabilitation of the entire Suwon Stream, inside and outside the Fortress, that was initiated in 2006. Finally, in June 2010, reconstruction work began and was completed in 2012. South-East Pavilion (동남각루) Dongnam Gangnu, the south-eastern pavilion, sits on top of a small rise above Namsumun (the South