Guihan Jiao(Collins Reef/Johnson North Reef), which lies in the southwest of Jiuzhang Qunjiao(Union Banks and Reef) of Nansha Islands(the Spratly Islands), was invaded by Vietnam in 1988 and occupied by it since then. The Reef is of a 4-angel pattern, about 2200m long and 1100m wide, and lies from northwest to southeast.
In 2015, a runway was newly built.
From 2016 to 2018, a new watchtower was built in the east of the former one.
