협궤, or "narrow gauge," refers to a railway system where the distance between the rails is less than the standard gauge of 1,435 mm. This type of railway is often used in mountainous or rugged terrain, where building standard gauge tracks would be more challenging and expensive. Narrow gauge railways can be more cost-effective and allow for tighter curves, making them suitable for specific regional needs. Many countries, including South Korea, have utilized 협궤 for various purposes, such as transporting goods and passengers in areas with limited infrastructure. These railways can also be found in tourist attractions, where they provide scenic rides through beautiful landscapes, showcasing the unique advantages of narrow gauge systems.