With a group of students from the University of Canterbury Engineering Geology program, I investigated the character of buried karst at the Cave Stream Reserve of Castle Hill Basin. We surveyed the cave using a laser distance meter and compass, then used RTK GPS to develop a high-resolution model of the Cave Stream carpark area. We integrated the cave and topography with geological mapping and scanline surveys in a Leapfrog model of the reserve. We then ran an MASW survey across the roof of the cave and incorporated the shear wave velocity map into the model.