Pembe Kayalar is a historic and natural area located near Kefken, in the Kandıra district of Kocaeli, which has been used as a quarry since ancient times.
Due to the geological composition of the stones in the region, they are soft when submerged in water but harden upon exposure to air once they are brought to the surface. Because of this property, the area was used as a quarry for a very long time. The rocks have taken on a pink and reddish hue due to the presence of iron oxide in their composition.
The quarry was also extensively used during the Ottoman period; stones cut into rectangular blocks were transported to Istanbul by sea to meet the stone requirements for buildings constructed there. Stones extracted from this site were used in numerous structures, most notably Rumeli Hisarı and the Sultan Ahmet Mosque.1
