Ingá Stone, Ancient petroglyph site in Ingá, Brazil

The Ingá Stone is a gneiss outcrop covering about 250 square metres beside the Ingá River in Paraíba. Its best-known face is a vertical wall 46 metres long and 3.8 metres high, of which a 15-metre stretch is almost entirely covered with carvings. The grooves are wide, up to 5 cm, and up to 8 mm deep, cut below a wavy line of 112 capsule-shaped incisions.

Carbon dating indicates that the rock carvings were made around 6,000 years ago, though floods deposited sediment that makes precise measurement difficult. In the 20th century, researchers began to document the carvings systematically and investigate their meaning.

The carved signs show animals, fruits, human shapes and sky objects that visitors can still recognize across the rock wall today. The astronomical patterns stand out because they show how the early people of the region watched the heavens.

The site is located 96 kilometers (60 miles) from João Pessoa and needs protection from vandalism and environmental damage. Visitors should stay on marked paths to avoid damaging the delicate carvings.

The Spanish engineer Francisco Pavía Alemany discovered a series of carved bowls that form a solar calendar tracking daily sunlight throughout the year. This arrangement shows that the creators of the carvings used astronomical knowledge to mark seasons and days.