This book presents a comprehensive experimental investigation, consisting of element scaletriaxial and simple shear tests and model scaleshaking table tests, to examine the monotonic and cyclic behavior of Skopje sand. Skopje sand is silica sand from natural alluvial river deposits collected from the river terraces of Vardar river in the city of Skopje, Macedonia. Numerical simulation of the element monotonic and cyclic tests is also presented using the hypoplastic material model. Particular focus is given on the liquefaction potential of the tested material. While there were no well-documented cases of liquefaction during the 1963 Skopje earthquake with a magnitude of 6.1, significant structural damage was attributed to pronounced site amplification effects of sand materials in the Vardar valley. Given the absence of seismic geotechnical codes in the region at that time, the lack of a seismic monitoring network, and limited knowledge about the city's geotechnical properties, there is the assumption that liquefaction might have occurred but went undocumented and unassessed due to the overwhelming structural damage and other post-earthquake disaster management activities. The generated experimental data of Skopje sand serve as a foundational dataset for students and researchers into continuous more advanced experimental research in the field, validating numerical modeling focusing on liquefaction phenomena, soil dynamics, induced settlement of buildings, and evaluating effective mitigation strategies. The conducted investigations provide a strong basis for sustainable research on element and model scale in the Laboratory for Soil Dynamics and Geotechnical Engineering at the Department of Geotechnics and Special Structures, Institute of Earthquake Engineering and Engineering Seismology-IZIIS, Skopje, Macedonia.