Well, one of the most prominence stones left behind is the “Unfinished' Obelisk,” taller than any known obelisk ever raised. The unfinished obelisk is located in the northern region of Aswan Egypt (500 miles south of Cairo). It is roughly one third larger than any ancient Egyptian obelisk ever erected. If this obelisk finished, then it’d have been measured 137 feet and weighed 1,200 tons. The creator of Obelisk started to carve it directly from bedrock, but cracks appeared in the granite and project was abandoned. However, the bottom side is still attached to the bedrock gives important clues to how the ancient quarried granite.
The unfinished obelisk is basically a Greek architecture, defined as a tall and slender monument with 4 sides converging to a mini pyramidal shape at the topmost point. The Unfinished obelisk was constructed by Hatshepsut, the queen of Thutmose II, who ruled Egypt as a Pharaoh from 1478 to 1458 B.C., jointly with Thutmose III, who was then only a child.
The abandoned project provides strange insight into ancient Egyptian stone working methods, notions the idea of tools they had used visible as ocher-colored lines marking where they were working. The Aswan area is the main region of providing red granite used for ancient temples and colossi came from quarries. The unfinished obelisk base was discovered in 2005 and still lies being hewn from the rock. Moreover, some rock carvings and leftovers may correspond to the area where most of fame obelisks were worked. Initially it was believed that the stone had an undetected flawless; however quarrying process let the cracking to develop by releasing the stress. The unfinished objects are an open-air museum and are officially protected by the Egyptian government as an archeological site
The purpose behind to done obelisk is not known, because the main tool employed for carving the granite were small balls of Dolerite. The unearthing of obelisk allows observing how they were made. Therefore, the means of separating the stone from the bedrock was a simple method used around the ancient world. Also small cavities were made in the stone, which were then filled with wood and soaked water causing it to expand. Source: Charismatic Planet