Reservoir re-housed, historical artifacts moved or rare environments relocated. Examples include the temples of Abu Simbel (which were moved before the construction of the Aswan Dam to create Lake Nasser from the Nile in Egypt), the relocation of the village of Capel Celyn during the construction of Llyn Celyn, and the relocation of Borgo San Pietro of Petrella Salto during the construction of Lake Salto. Construction of a reservoir in a valley will usually need the river to be diverted during part of the build, often through a temporary tunnel or by-pass channel. In hilly regions, reservoirs are often constructed by
Abu Simbel temples as a lasting monument to the king and his queen Nefertari, and commemorate 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, 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 Nile River.