This open access book includes the select, peer-reviewed proceedings of the 2nd International Geotechnical Innovation Conference (IGIC 2025) held in May 2025. This book is a compilation of research and case studies relevant to geotechnical engineering challenges in mega and giga projects across Saudi Arabia and the Gulf region. With rapid infrastructure development in the region, geotechnical engineering has become increasingly critical in ensuring the stability, efficiency, and sustainability of large-scale projects. This book covers deep foundations, soil stabilization, soil mechanics, geotechnical site characterization, and risk assessment, among other key topics. It highlights real-world case studies, offering insights into innovative solutions for high-profile projects in challenging environments such as coastal, desert, and urban terrains. The contributions in this book are curated by experts, researchers, and industry practitioners who have contributed to various engineering and development of complex geotechnical projects. The book aims to bridge the gap between academic research and industry applications, providing valuable technical knowledge and best practices for infrastructure resilience, sustainability, and optimization.