Hem (alleyway)

Hem (Hẻm) or Ngo (Ngõ) are the terms used to describe narrow streets branching off of main roads. Hem are characterized by their narrow width and are lined with narrow, multistory buildings known as tube houses, creating a dense and vertical urban form.

In 2016, 85% of residents in Ho Chi Minh City and 88% in Hanoi lived in hem alleyways. Hem are numbered and referred to by the name of the major street it branches off of, similarly to Sois in Thailand. Slashes are used to indicated an address in a hem, so the address "36/23 Hẻm Lê Thị Riêng" indicates the house is number 36 in the 23rd Hem off Lê Thị Riêng street.