1) Basement access 2) Basement entrance 3) Cellar access 4) Cellar door approach 5) Courtyard space 6) Excavated access 7) Open space between buildings 8) Passage to a basement door 9) Passageway 10) Playground of a sort 11) Space for cellar ventilation 12) Sunken court 13) Sunken passage 14) Sunken space 1) Yard 
An open subsurface space adjacent to a building used to admit light/air or as a means of access to a basement. 
[n] - a passageway between buildings or giving access to a basement
noun a passageway between buildings or giving access to a basement
a sunken area leading to a cellar or basement entrance, or in front of basement or cellar windows. · a passageway, esp. one between buildings.