I stumbled across some pictures of these temples recently, the Temple of Jupiter and the Temple of Bacchus. They are two of the three temples that once made up the temple complex of Baalbeck. You can read about them here so I wont go into too much detail. The thing that really struck me though was the size of the base stones, they are colossal. Estimates put some in the vicinity of 1,000 tons in weight. That they were able to move these is astonishing, there's a theory on how that was done in the link above. The Romans simply knew how to build...

Artists impression of the complex layout
A stone left at the quarry
Base stones with humans for scale

Another shot of the stone still at the quarry

Temple of Jupiter : c. 1870-1885
Temple of Jupiter 1891