"Journey to the Lost City" is not a specific film by Fritz Lang but the combination of Der Tiger von Eschnapur (1959) with its sequel Das indische Grabmal (1959), done in 1960 by American International Pictures.

An architect travels to the remote city of Eschnapur to oversee some work being done at the bequest of the local Maharajah. Along the way the architect meets and falls in love with a beautiful temple-dancer. The Maharajah also loves this dancer and plans to marry her despite fierce opposition from factions within his own court. The dancer responds to the architect's advances and they flee from Eschnapur but are captured by the Maharajah's soldiers. To save the architect's life, the dancer agrees to marry the Maharajah. This sparks a revolt which is eventually put down. The sadder but wiser Maharajah then allows the architect and the dancer to leave his domain.—dinky-4 of Minneapolis