‘Most sophisticated tunnel in US history’ discovered between Mexico and Arizona
US border officials claim an incomplete tunnel found stretching from Mexico to Arizona could be ‘the most sophisticated tunnel in US history’. The tunnel runs from San Luis Río Colorado, Mexico, to San Luis, Arizona, where it stops short of reaching the surface. It is 3ft wide and 4ft high (1 x 1.3 metres). Smugglers have been using tunnels to get drugs and people across the border for decades.