The small old district of Areatza is notable due to its mix of buildings with rural and urban architecture.
It is located parallel to the Arratia river, and has both typical and religious houses. The Town Hall square contains the most aristocratic building in the old district: Gortazar Palace. The lower floor in dressed ashlar stone corresponds to the end of the 16th century, whilst the upper floors, in brickwork, date from the first third of the 17th century. Most notable are the paintings which adorn the facade.
The Town Hall is from the 19th century, of neoclassical style. The portico on the lower floor has eleven semicircular archways. The doorway of San Bartolomé Church is also worth visiting.