The relative pronoun where is used when a physical location is being referred to. Where is also often used when identifying variables in equations or in figures.

The lab where the element was discovered burned down in 1902.

The relationship between the displacement field, the electric field and the polarization is D = ε0E + P, where ε0 is the electric constant.

Where can also be used to refer to publications, although the phrase “in which” is more formal than where in these cases.

Arwill-Nordbladh wrote a compendium of gender theory in archaeology, where she argues that archaeology is androcentric in numerous ways.