The dataset characterizes four boreholes near Kemnader See, located on the outskirts of Bochum city, Germany. The boreholes were drilled for research purposes and are owned by Ruhr-Universität Bochum (RUB). Beside the key borehole attributes, including location, geometry, construction details, and orientation, the dataset includes measurements of temperature, conductivity, resistivity, density, gamma ray, and travel times of P- and S-waves. The data also contains sonic logs, amplitudes of the reflected waves, and images of the borehole walls. The data were recorded by DMT GmbH, an engineering and consulting company.