Surrounded by the Mediterranean macchia, this cove is originally shaped as an arch and can be reached passing Liscia Ruja, through a path on the left.
This beach is not too crowded even during the peak season and, therefore, not to chaotic.
It stretches over about 250 meters and is characterized by the presence of red shaded pebbles and rocks that give the name to the beach.
The sand is white and fine, while the sea, crystalline and very clear, takes on tones ranging from deep blue, clear blue, to green emerald.
The bottom is shallow and suitable for children.
In 2013 the Italian Goletta verde Legambiente association awarded the coast of Arzachena with the prestigious 4 sails, inserting Petra Ruja among the absolutely not to miss beaches.