Helkar was a great tower, raised by Melko to house the southern of the Two Lamps fashioned by Aulë to illuminate Middle-earth. The tower was extremely tall, rising to the stars, and shone like pale blue crystal. Melko claimed that Helkar and its northern twin Ringil were made of a strong, imperishable substance that he had devised; in reality he lied for they were made of ice (a material unknown to the other Valar). Thus, when Aulë's lamps were placed upon them (silver in the north and gold in the south) the ice melted and caused great floods to pour into the seas.
Other versions of the legendarium
Christopher Tolkien noted that the story of the Lamps in its early stage was very different from the published Silmarillion. It is Melko, not Aulë, who built the two towers. The name Helkar disappeared as the name for the southern tower; eventually the Sea of Helcar would be the body of water formed at the roots of Illuin, the northern tower and lamp. The only remaining influence from the older version of the story was that the fall of the towers created inland seas, a vestige of the notion that the towers had been made of ice that melted.
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Book of Lost Tales Part One, "III. The Coming of the Valar and the Building of Valinor", pp. 69-70
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Book of Lost Tales Part One, Appendix: Names in the Lost Tales – Part I, entry "Helkar"
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Book of Lost Tales Part One, "III. The Coming of the Valar and the Building of Valinor": "Notes and Commentary", p. 87