Egyptian temple Debod, as gifts to nations that had contributed to the preservation effort. Nevertheless, several other temples vanished beneath the lake. Today there are dozens of sites with substantial temple remains, although many more once existed, and none of the major temples in Lower or Middle Egypt are well preserved. Those that are well preserved, such as Karnak, Luxor, and Abu Simbel, draw tourists from around the world and are therefore a key attraction for the Egyptian tourist industry, which is a major sector of the Egyptian economy. Three temple sites—Ancient Thebes with its Necropolis, Memphis and its Necropolis, and the
Kazimierz Michałowski were discovered under the "church of the columns". The second building based on the cruciform plan was also explored as well as a mosque which turned out to be erected on a former royal palace and not (as previously assumed) on a Christian temple. Polish archaeologists discovered also a baptistery. Since 1966 a Polish mission was performing parallel prehistoric excavations in the vicinity the village of Gaddar. Professor Michałowski did not excavate in Abu Simbel but along with a team of Polish archaeologists he took part in the salvaging of rock temples of Pharaoh Ramesses II, which were at risk