Though the Alps form a barrier they have never formed an impassable barrier, since, from the earliest days onwards, they have been traversed first, perhaps, for purposes of war or commerce, and later by pilgrims, students and tourists.
The Alps form a barrier. They have never formed an impassable barrier from the earliest days onwards a barrier. This was since. They have been traversed first for purposes of war or commerce, and later by pilgrims, students and tourists. This was perhaps.