Group A was once the grandest complex at My Son — the sacred centre of the Champa kingdom's religious life, built around the great kalan A1, which French archaeologists described as the finest Cham temple on the site. It was dedicated to Sambhu-Bhadresvara, the composite deity linking the historical king Bhadravarman I with Shiva, and it stood at the heart of a walled complex with subsidiary towers and enclosing walls.
In August 1969, American bombing raids — targeting North Vietnamese Army troops who were using the ruins as shelter — destroyed A1 and much of the surrounding complex. The rubble and bomb craters are still visible. Walking through Group A today is a deliberately unsettling experience: foundation outlines in the grass, broken carvings half-buried, and the knowledge of what stood here within living memory. The site's UNESCO designation came in 1999, thirty years after its single most destructive moment.