Discussion of holes in the stratospheric ozone layer usually revolves around investigations of the thickness of the layer near the South Pole. This online activity allows users to study the thickness of the ozone layer over any location on Earth to see how it has changed over time. This is done by plotting historical data from the Total Ozone Mapping Spectrometer (TOMS) Program, which has been in operation since 1978. Users are allowed to select their own location on Earth and the period over which they plot the data. A link to TOMS datasets is provided.