Just past the Akapana Pyramid is the Sunken/Semi-Subterranean Temple.  This temple has walls covered with stone carved heads with 3 monoliths in the center.  I like this temple a lot and chanted mantras in it.  The acoustics of the temple make me feel that the builders designed it with sound/toning/chanting/singing in mind.

The other feeling I had about this temple is that it reminds me of the stelae at the Mayan city of Copan.  Specifically, it feels like these stone heads represented all of the races of people who came to Tiwanaku to visit; sort of a cultural museum.

An amazing 24 foot tall monolith was excavated from this courtyard.  The Bolivian Government put it in the site museum and does not allow anyone to photograph it.  Hence, I have no photos of it.  According to my LONELY PLANET Guide and Rosse Mary the monolith represents Pacha Mama, Mother Nature or Mother Earth.  The archeologists call it the Bennett Monolith after the guy who excavated it.