Street naming in Antigua differs from that of other Guatemalan cities. Avenidas (avenues) run north-south, beginning with 1 Avenida in the east and increasing in number as you go west. Calles (streets) run east-west, beginning with 1 Calle in the north and increasing in number as you go south. Avenidas split into norte (north) and sur (south) at 5 Calle, the Palacio de Capitanes Generales side of the Parque Central. Calles split into oriente (east) and poniente (west) at 4 Avenida, the cathedral side of Parque Central. Building numbering begins at these points and continues sequentially without regard to blocks. Numbers on one side of the street increase independently of those on the opposite side, meaning that the 40s sequence might be across the street from the 20s. Take heart: the complex system does make some sense once you see it yourself.