Predicting where water goes and how fast in the unsaturated zone is critical for understanding aquifer recharge, contaminant transport, hazards, and other hydrologic issues. Water that infiltrates at the land surface is transported by various mechanisms. For example, water may move rapidly through vertical preferential flow paths, laterally along lithological boundaries, or more slowly as diffuse flow through soil or rock matrix. Different theoretical and experimental approaches have been developed to increase the knowledge of this portion of the subsurface but still there are gaps in comprehension and quantification of rapid flow processes that occur in the unsaturated zone. Contributions of both theretical and experimental studies that differ from the traditional theories and tools are welcome to enhance our knowledge and spark discussion of how we can quantify various mechanisms for fluid and susbstance movement in the unsaturated zone.