The Sunlight Forge was a cut area from Legacy of Kain: Soul Reaver. It was removed due to duplicity and lack of time along with the other forges. Only the Fire Forge survived in the final game and they all had the same overall basic design.
The forge has a prolonged layout with the imbuement basin at its end. The basin appears to have lenses installed to magnify the sunlight coming from a hole in the ceiling.
Daniel Cabuco specified that each forge was adjacent to a boss room. In this case, it is possible it was near Turel´s Smokestack or in the Lighthouse valley as it shares the same specific rock texture as the surrounding mountains of the Lighthouse.