Pantai Wisata Onggaya seems to be a mix-up in the search results, as the name does not specifically match the location provided (Lk III Pasar Sorkam, North Sumatra, Indonesia). However, if we consider the confusion might stem from a similar name in Merauke, Papua, Pantai Onggaya there is known for its distinctive red-white sand and array of shells. This beach offers a serene and visually striking experience with its turquoise water.
The confusion in locations makes it challenging to provide accurate information about the specific beach in North Sumatra.
Generally, beaches in Indonesia are celebrated for their rich biodiversity and stunning landscapes, but without specific details on Pantai Wisata Onggaya in North Sumatra, it's difficult to tailor this description further.