General Havana Information - Real Havana: Explore Cuba Like a Local and Save Money - page 86

Addresses
Addresses are typically written down as being located between one street and an-
other. The Spanish word for between is entre , and it is usually abbreviated as e/.
So, the address of a building located on G Street, between 23 and 25, would be
written as Calle G e/ 23 y 25. If a building is at the corner, then the Spanish word
esquina is used (abbreviated as esq .). A location at the corner of 23 and M would
be written as Calle 23, esq. M.
Sometimes the words bajos and altos are also used in addresses to indicate the
level of a particular apartment. If the apartment is located on the ground floor, it
would be referred to as a bajos (low) unit. A top floor apartment is called an altos
(high) unit.