This is...

The Wachusett Reservoir Dam,  largest hand built Levee still in use in all the world, dedicated in 1906 if I am not mistaken.

And I hope to Hell someone is keeping up with inspections on this sumbitch BETTER than whoever was tasked to keep an eye on the Alewife MBTA Parking Garage...cuz a couple of thousand people live downstream of this dam...just saying thats all.