Short answers, pulled from the story.
The Nile Delta covers approximately 240 km of Mediterranean coastline from Alexandria in the west to Port Said in the east, and extends about 160 km from north to south. It is one of the world's largest river deltas, beginning from Cairo.
About 70 million people live in the Nile Delta region. Outside major cities, population density averages 1,000 people per square kilometre or more. Cairo is the largest city in the delta.
The Rosetta Stone was found in 1799 in the port city of Rosetta, an anglicised version of the Arabic name Rashid, located in the Nile Delta.
In July 2019, excavations at Heracleion led by underwater archaeologist Franck Goddio uncovered a small Greek temple, ancient granite columns, treasure-carrying ships, and bronze coins from the reign of Ptolemy II dating to the third and fourth centuries BC. The city's main temple was also found on the seafloor off Egypt's north coast.
The construction of the Aswan Dam ended the Nile's annual flooding cycle that once delivered nutrients and sediments to the delta. Without that supply, floodplain soils have become poorer and farmers now depend heavily on artificial fertilisers. The dam has also removed the sediment that naturally rebuilt the coastline, leaving the delta more vulnerable to erosion and sea level rise.
A 1 metre rise in sea level could put an estimated 887 thousand people at risk of flooding and displacement, and could destroy roughly 402 km2 of cropland and 47 km2 of urban area, flooding approximately 450 km2 in total. If polar ice caps were to melt, the ancient port city of Alexandria could disappear beneath the Mediterranean. Climate projections suggest the delta could generate as many as seven million climate refugees by the end of the 21st century.