The first step in building most megalithic monuments was quarrying the stone. Most megalithic construction occurred in stone-age societies. Therefore, quarrying was generally performed with rock tools. Considering the biggest stone at Stonehenge is approximately 25 tons, the quarrying process must have required considerable time and labor. Although the megaliths on Easter Island were built much later, they were also carved with stone tools. Egyptian obelisks may have been quarried using blows by dolorite balls.
The transportation of giant monoliths presents perhaps the greatest mysteries and grounds for conjecture. A stone obelisk erected by Queen Hatshepsut at Karnak, Egypt weighs approximately 343 tons. An inscription on the obelisk mentions that transport took seven months. On transportation technique, likely used for the obelisk, was to place the monolith on wooden sledges that were drawn across track, perhaps by ropes attached to draft animals. The Egyptian obelisks and Stonehenge megaliths were probably also transported in part over water through the use of large barges.
Many cultures probably used trees as rollers to transport large stones. This method appears likely on Easter Island. The island was almost totally forested prior to construction of the stone heads, with the forests gone by 1650, about the time construction ceased. Hundreds of the megaliths were carved and transported to various sites on the island, in many cases over 15 miles from the quarry site. Most likely, the islanders used logs as rollers, decimating their forests in the process.
Once megaliths were quarried, carved and transported, they often needed to be placed in an erect position. First a hole was dug to a depth that would ensure the monolith would stay anchored and upright. A large ramp was necessary to raise the base of the monolith, with the top of the ramp acting as a fulcrum. As the stone was dragged into place, the base would be suspended over the hole atop the ramp. Ropes would then pull the base down into the hole. From that point, the stone was lifted in small increments, the ramp continually built up underneath, until finally the monolith could be pulled into an erect position.