It is highest at its narrowest part.
The gauge may be regarded as reduced to its narrowest possible dimensions in mono-rail lines, where the weight of the trains is carried on a single rail.
Such a view can recommend itself to only the narrowest of minds.
The sea is connected with the Arctic Ocean northward by Bering Strait, at the narrowest part of which East Cape (Deshnev) in Asia approaches within about 56 m.
The occupation of these topmost ridges must greatly assist in a further advance across the peninsula here at its narrowest point.