You might be able to tell from the website, but here at House of Modern Vintage we're obsessed with all things blue & white.  Delft, Blue Willow, Blue Danube, any handpainted chinoiserie...the list really goes on (and on).
 
Vintage Blue Danube Flat Cup & Saucer Set
set of four
perfect condition
 
approx 2.5" in height, 3.5" across