Ciudad Encantada de Bolnuevo, Natural monument and rock formation in Bolnuevo, Spain.

Ciudad Encantada de Bolnuevo, also called Las Gredas de Bolnuevo, is a set of eroded sandstone formations along the beach at Bolnuevo, Murcia. Wind and water have carved the soft rock over thousands of years into mushroom shapes and near-vertical pillars that appear to defy gravity. The yellowish stone is clay rich in sand.

The rock layers date to the Pliocene period around 4.5 million years ago, forming in an ancient marine environment. Microfossils embedded within reveal the presence of sea life during that distant geological time.

The rock formations serve as an educational site where geologists and students examine the effects of natural weathering processes on coastal landscapes.

The site is located about five kilometers from Mazarron and is freely accessible year-round. Visitors can explore on foot and take advantage of nearby Mediterranean beaches for additional coastal enjoyment.

The yellow colour comes from the large amount of sand mixed into the clay, not from the clay itself. The rock also holds microfossils from the Pliocene, roughly 4.5 million years old, so the formations are the remains of a seabed that was later lifted and carved by water and wind.