Chestnut Hill penthouse comes with 1,300-square-foot private deck

The cavernous 1,730-square-foot Penthouse 6 at 2420 Beacon Street in Boston’s slice of Chestnut Hill is impressive enough on the inside: Double-height ceilings, a floating fireplace, multiple levels, geometric windows, and a staircase with a sizable landing.

But the most striking feature of the unit in the converted Beaux Arts Whitehall building of the old Waterworks complex is its 1,300-square-foot-plus private deck.

The whole shebang, including two parking spaces, is on sale now through Compass for $1.2 million.