Maps often make the Mediterranean Sea look like a vast barrier between Europe and Africa. However, the two continents are remarkably close at the Strait of Gibraltar. At its narrowest point, the distance between Spain and Morocco is only 14.3 kilometers (8.9 miles). On a clear day, one can easily see the coastline of Africa from the southern tip of Europe. There have even been recurring proposals to build a bridge or an undersea tunnel to connect the two continents. This proximity explains why the region has been such a focal point for migration, trade, and cultural exchange for thousands of years, and why the 'Pillars of Hercules' were so significant in ancient geography.