Abu Simbel are two massive rock-cut temples in the village of Abu Simbel, Aswan Governorate, Upper Egypt, near the border with Sudan. They are situated on the western bank of Lake Nasser, about 230 km (140 mi) southwest of Aswan (about 300 km (190 mi) by road). The complex is part of the UNESCO World Heritage Site known as the “Nubian Monuments”, which run from Abu Simbel downriver to Philae (near Aswan), and include Amada, Wadi es-Sebua, and other Nubian sites. The twin temples were originally carved out of the mountainside in the 13th century BC, during the 19th Dynasty reign of the Pharaoh Ramesses II. They serve as a lasting monument to the king Ramesses II. His wife Nefertari and children can be seen in smaller figures by his feet, considered to be of lesser importance and were not given the same position of scale. This commemorates his victory at the Battle of Kadesh. Their huge external rock relief figures have become iconic.
The complex was relocated in its entirety in 1968 under the supervision of a Polish archaeologist, Kazimierz Michałowski, from the Polish Centre of Mediterranean Archaeology University of Warsaw, on an artificial hill made from a domed structure, high above the Aswan High Dam reservoir. The relocation of the temples was necessary or they would have been submerged during the creation of Lake Nasser, the massive artificial water reservoir formed after the building of the Aswan High Dam on the River Nile. The project was carried out as part of the UNESCO Nubian Salvage Campaign.
Information from Wikipedia
https://en.wikipedia.org/wiki/Abu_Simbel#History