In the initial plans of the Metro's development, there was no provision for the Circle line. Instead it was planned for complete cross-city routes ("diameters") to cross the city centre with interchange stations at their intersections. However, after the opening of the second stage in 1938, it was clear from the excessive loads on those junctions, that this plan would be insufficient to deal with the growing number of passengers as the system expanded. An urban legend suggests that Joseph Stalin himself suggested the line when he placed a coffee cup on the original development map (with no ring) and then lifting it and leaving a circular stain around the centre of the city and said "It's your main fault, it should be built". It is thought this is the reason for the line's brown colour on all metro maps.