Some of these blocks of ice stand up to 2.4 kilometres high and show signs of being violently rammed up against each other.
NASA has provisionally named the region the al-Idrisi mountains.
The plain within the heart-shaped region, named informally Sputnik Planum, can be seen in the false colour image of Pluto below. It consists of soft, nitrogen-rich ices that form a nearly level surface.
This view above is about 80 kilometres wide.