Playa San Antonio, often referred to as Playa San Antonio (Principal), is a beach located in Pichilemu, Provincia de Cardenal Caro, Chile. It is situated directly in front of Parque Ross. The beach provides direct access for paddlers launching from shore, with amenities including public showers, bathrooms, changing rooms, and a parking lot for vehicles. The beach is considered suitable for swimming and is noted for presenting excellent conditions for surfing, indicating a shore-break and wave activity that paddlers must assess for their skill level and craft type. The surrounding area features wide staircases with balustrades descending from Parque Ross and a lookout terrace on the rocks at the southern end of the beach. The overall character is that of a developed municipal beach with infrastructure catering to visitors. The beach's exposure to Pacific Ocean swells makes it a potential launch point for coastal exploration, with notable nearby destinations including Punta de Lobos, a renowned surf spot located approximately six kilometers to the south, characterized by a high cliff and rock formations frequented by sea lions. Another nearby feature is the Infiernillo beach to the south, known for its rock formations where waves break. The region's cultural significance is highlighted by nearby national monuments, including a historic building designed as a miniature replica of the Trianon palace.