Plaeng Nam is about 100 m (328.1 ft) long. In the past, it was a place for garbage dumping of locals because it was close to the wet market. Therefore had a foul and dirty condition even the name was called Trok Pacha Ma Nao (ตรอกป่าช้าหมาเน่า; lit: "lane of carrion graveyard"). Until the reign of King Prajadhipok (Rama VII), he improved the conditions of the city, including various utilities. So, he gave the official name Plaeng Nam for auspiciousness, which can be literally translated that "renaming".[1]
At the entrance of the alley on Charoen Krung side is a Wat Mangkon Station (BL29) located, the extension MRT Blue Line. This station built with Sino-Portuguese in order to harmonize with the surrounding buildings which is a historic area.[4]