Challenge International de Tourisme 1934
The Challenge 1934 was the fourth and last FAI International Tourist Plane Contest (French: Challenge International de Tourisme), that took place between August 28 and September 16, 1934, in Warsaw, Poland. The four Challenges, from 1929 to 1934, were major aviation events in pre-war Europe.
Source: Wikipedia — Challenge International de Tourisme 1934 (CC BY-SA 4.0)