Learners build models of sinkholes to gain an intuitive knowledge of their physical aspects. They construct a model of the geology of a sinkhole in a terrarium using sugar and sand to represent the different types of soil. They then saturate the model so the sugar dissolves and the sinkhole appears. They also can use a spray bottle to simulate the addition of a well to the system that drains out groundwater, causing the sinkhole to open wider. The lesson plan includes handouts, background information, and suggested extension activities.