The Borgo dei Bassi is the most distinctive feature of Erli's urban layout — a small settlement built on an elliptical plan, with houses arranged in a continuous oval that originally formed a defensive perimeter. This type of layout, designed to present an unbroken wall to the outside, is found at various points along the Salt Road through the Ligurian Alps and reflects the insecurity of medieval mountain communities.
The borgo is well-preserved and the elliptical form is still clearly readable from a viewpoint above. Walking through the narrow lanes inside the oval takes only a few minutes, but the architectural logic repays a slow look.