Jūratė (Jūratė and Kastytis)

In the popular Lithuanian legend Jūratė lives in a magnificent amber palace beneath the Baltic Sea. She becomes enamored of a mortal fisherman named Kastytis and brings him to live with her in the palace. The affair angers a thunder deity identified in some retellings as Perkūnas (Perkunas), who destroys the amber castle; the fragments of the palace or the goddess' tears are offered in various sources as an etiological explanation for the amber that washes ashore.

Sources variously describe Jūratė as a sea‑goddess, a mermaid, or an undine; she is portrayed as a female supernatural aquatic figure associated with an undersea amber palace. While some retellings call her exceptionally fair, the supplied materials do not give fixed physical detail beyond her humanlike female form and aquatic association and the visual motif of the amber castle.

In the legend Jūratė forms a close relationship with a human (Kastytis) and is portrayed as capable of interacting with the human world from her undersea realm. Some versions recount that she sent mermaids to warn Kastytis about his fishing, indicating communicative or interpersonal influence in retellings; she is primarily characterized by love and grief rather than catalogued supernatural powers in the provided sources. The main demonstrated vulnerability in the tale is to the thunder god's destructive action.