Located near the main square along the malecon, these arches seem to be placed here to give the city an added classical ambiance. There is no sign at the site to explain there placement here.
This website (
visit link) discusses them:
"One of the most iconic and recognizable landmarks of Puerto Vallarta, Los Arcos refers to the row of arches in the oceanfront square of Plaza Morelos on the city's southern end. The dramatic seaside arches also serve as an amphitheatre. Los Arcos is a great place to stroll during the evenings, especially along the Malecón, the oceanfront walkway that runs along a portion of the Bahía de Banderas (Banderas Bay). Here you'll find an assortment of sand sculptures, statues, art pieces, street performers and merchants. Free cultural performances on the Malecón and at Los Arcos are standard during the weekends."