Segais

Segais, also known as the Well of Segais, is a prominent feature in Irish mythology. It is described as a magical pool associated with wisdom and, in some versions, as the source of the River Shannon. The well is frequently linked to the Otherworld and is said to lie beneath or near the sídhe (fairy mounds) in various traditions.

A central image around Segais is a grove of seven hazel trees that overhang the pool. The nuts from these trees continually fall into the water, and the pool’s lore holds that the seven hazels are a conduit of knowledge. A salmon dwelling in or near the well is named the Salmon of Knowledge, a creature believed to have absorbed the wisdom from the hazelnuts that drop into the water.

The most well-known legend connecting Segais to a human hero concerns Finn mac Cumhaill (Fionn mac Cumhaill). Finn is apprenticed to the wise Finnegas and entrusted with guarding the Salmon of Knowledge. When Finn tastes a fragment of the salmon’s flesh, he gains extraordinary wisdom and the power to understand all arts and learning. This moment marks a pivotal point in the Fenian Cycle, with Finn’s acquired wisdom shaping his later deeds as a leader and warrior.

In scholarship and folklore, Segais functions as a symbolic locus where wisdom, nature, and the Otherworld intersect. Variants of the tale place the well in different locations or frame it as the ancestral source of the Shannon, reflecting broader themes of knowledge and origin that permeate Irish myth.