Placement of Ancient Stones

When the founders of Nedev set about exploring the lands that they had won from the Red Blade tribe of Goblins, they came across many ruined towns, fortresses, temples and monuments in the area. While still trying to piece together the information they have on this lost ancient civilization, one of the biggest mysteries they have is how did they build these places in the first place?
Large stone blocks were used in the construction of these places. Even the statues and obelisks seem to be made out a single piece of stone, yet their have been no quarrys found, nor any evidence of roads, or large wagons to transport the stone from the distant mountians to the east. Some sages have theorized that perhaps the places where these structures were built was once a large stone mountain or hill, and they simple carved away the rest. But others have ridiculed that idea, asking where the carved away pieces are located now. One adventurer offered that perhaps trained, or friendly, dragons carried the stone to the locations and helped place it, or perhaps giants carried it in from the mountians, but there is no evidence of either of that in any of the artworks found so far.
Ove the years the examination of these locations has determined that while some very lasrge blocks do exist, and most of the obelisks and statues are carved out of a single stone, that the buildings are definately made of many large stones, but are placed so well together as to make the seams almost invisible.
At least one sage, Detrulius the Younger, has dedicated much of his efforts to solve this mystery, for in the means to move large stones a great distance, and place them without seams, can be discovered, that would make someone very wealthy, and world-famous.