The interplay of circles, squares and crosses formed by their positions and angles is culturally significant. The ‘piscina’ walls slope gently outward at an angle of 15 degrees to aid stability. One ‘piscina’ contains a monolith with phallic fertility symbol. ‘Piscinas’ were connected by a network of channels to transport water.

Water was a key feature of Yumbo life, having both curative and purifying properties. Like a giant mirror reflecting the heavens, the large circular ‘piscina’ permitted the shamans to observe the passage of sun and moon. The waters in the ‘piscina’ in effect, imprisoned the moon, trapping it in the world below. Believers would throw small stones from the river into the ‘piscinas’ as part of a ritual, receiving the spirit of the water, manifested in concentric circles.

The geometry of the circular ‘piscina’ is fascinating – its round shape a symbol of perfection, eternity and infinity. The circle imitates both the shape of the full moon and the sun and possibly mother nature in gestation. It is formed of 5 concentric stone circles, and archaeologists have discovered a significant fall of shadow on the access ramp on 6 May – the date immediately between the spring equinox and summer solstice and the date the rains end and summer begins.

A large rock in the nearby river has petroglyphs with concentric circles, spirals and anthropomorphic designs, representing both the male and female reproductive organs and symbolising eternity, infinity, life, earth, mankind, divinity and fertility