This area mostly covers the Central Catchment nature reserve area which spans the major water collection reservoirs of Upper Seletar Reservoir in the north, Upper Pierce and Lower Pierce Reservoirs in the middle (occupying most of this map area), and MacRitchie Reservoir in the south.
The major road shown here is Upper Thomson Road which runs north-south along the right edge of the map, with two of its main junctions, one to Yio Chu Kang Road and the other to Ang Mo Kio Avenue 1, appearing about one-third of the way in from the top and bottom edges of the map respectively.