Egyptian archaeologists carrying routine excavations at the so-called “Avenue of Sphinxes,” have unearthed the remains of a 5th century Egyptian Christian church and a "nilometer," a structure used to measure the level of the Nile during floods.
Already announced by Dr. Sabry Abd El Aziz, head of the SCA's Egyptology sector, in a 2008 Discovery News exclusive interview, the Avenue of Sphinx project involves the restoration of a 2.7-km (1.7-mile) ancient processional avenue that connects the grand temples of Luxor and Karnak on the east bank of the Nile River.
Built some 3,400 years ago, the alley was guarded on both sides by 1,350 majestic statues in the shape of sphinxes -- mythological creatures with the body of a lion and head of a human or ram.
The pathway, complete with rest places, chapels and sphinxes with ram heads, was originally built by King Amenhotep III (1410-1372 B.C.). It was then reconstructed by the 30th Dynasty King Nectanebo I (380-362 B.C.), who replaced the ram-headed sphinxes with his own head.
http://news.discovery.com/archaeology/ancient-egyptian-nilometer-helped-measure-rivers-height.html