Switzerland has built a huge tunnel network stretching over 2,544 kilometres with 1,852 tunnels. These tunnels carry roads, railways, water, and power beneath its mountains. The country started large tunnelling projects after 1950, first for hydroelectric power, then for roads and railways. Today, about 10% of both its motorway and railway routes run underground, a world record. The Gotthard Base Tunnel, opened in 2016, is the longest tunnel globally at 57 kilometres, allowing trains to cross the Alps with less energy and time. Beyond the Alps, tunnels are also built under growing urban areas like Zurich, Basel, and Berne to reduce congestion. Swiss cities have new underground stations and tunnel systems supporting daily travel. This extensive network not only bypasses difficult terrain but also reduces noise and land use on the surface. With ongoing expansions, tunnels remain key to Switzerland’s transport and infrastructure success.