The "Lost City" which was made famous by the Indiana Jones movie, Raiders of the Lost Ark is Tanis. Tanis is a city that is relatively unknown among Egypt's wealth of historical sites, though it has yielded one of the greatest archeological discoveries ever. Once the capital of all Egypt, Tanis's royal tombs have yielded artifacts which equal the treasures of Tutankhamun.

Today, it is called Sân el-Hagar and many worldwide who know of Tanis mostly remember it because it was portrayed in the movie, Raiders of the Lost Ark. In that famous film, the city was buried by a catastrophic ancient sandstorm and rediscovered by Nazis around 1936, searching for the Ark of the Covenant.

In reality, experts tell us that the Ark was never hidden in Tanis. Also it is considered fiction to believe that a great sandstorm destroyed and buried the city until it was discovered by Germans just outside of Cairo. These events never happen, and the Nazis never battled Indiana Jones in the site's ruins. The truth is that Tanis was capital of the 21st and 22nd Egyptian dynasties, during the reign of the Tanite kings. Tanis's advantageous location in these ancient periods enabled it to become a wealthy commercial center long before the rise of Alexandria, a Mediterranean port city in Egypt.

More Info: en.wikipedia.org