In the summer, when many places have entered the scorching sunny days, the peak of Phja Oắc (Nguyen Binh, Cao Bang province) offers a completely different atmosphere – cool, humid, covered in clouds, and blooming with hydrangeas. The climate and soil conditions in Phja Oắc are quite suitable for hydrangeas, so the plants grow very vigorously, with each flower displaying vivid colors and blooming round and full, crowding together to shine, obscuring the lush green leaves behind, looking extremely attractive.