The Land of Foam also known as At the Edge of Oikoumene (Russian: На краю Ойкумены, romanized: Na krayu Oikumeny) and Great Arc (Russian: Великая Дуга, romanized: Velikaya Duga) is a novel written by Soviet writer Ivan Yefremov in 1946.

The first part takes place during the rule of the pharaoh Djedefra (26th century BC), who decides to send an expedition to the South, in order to seek the famous and fabled Land of Punt and to seek the limits of the land and the start of the Great Arc, the circular ocean encompassing the entire world in Egyptian cosmology.

[2] A young sculptor named Pandion sets off on a journey to Crete, but he ends up on Phoenician Trading Ship ( while trying to escape captivity from some local wild Crete people), and after 4 days, he jumps the ship in the middle of the storm ( while escaping sacrifice from frightened sailors), and a storm finally lands him in Egypt, where he is enslaved.

He manages to win his freedom and find friends and after a long and perilous journey through African savanna and jungle comes back home.

In a short framing narrative, modern researchers examine the cameo and contemplate its possible origins.