A few thousand years ago as the last age was melting, what is now Montreal was mostly at the bottom of a huge sea. Gradually the water levels fell and islands appeared. This bank was once a lakeshore shelving down into the water and this forest is now growing on what was once a sandy beach.
Maybe a century ago this was cleared farmland as the collapsed dry-stone wall in the foreground indicates. Now it has reverted to typical mixed forest of the region – full of birds and interesting creatures.