With the ongoing efforts to clean up the city’s rivers and waterways, one waterway that perhaps needed to be given more attention to is the San Juan River. Known as one of the tributaries of the Pasig River (Metro Manila’s main waterway) the San Juan River traverses all the way up north in Quezon City (marked by the purplish ink on the map above) It also serves as a natural boundary for a part of eastern Manila, northwest Mandaluyong, west San Juan, and part of southwestern Quezon City.