Koreans are good at sleeping anytime, anywhere. It's because they practice sleep-deprivation in their jobs and schools at a scale I've only ever witnessed in US culture during basic training in the US Army. I recently ran across a picture taken, apparently, at the national legislature at Yeouido (in Seoul).
There's something truly awesome about this picture. Even the legislature looks just like a subway car or business office during break time.
The picture was found at a posting on Nate (a Korean web content portal) entitled 여의도의 흔한 피씨방 [Yeouidoui heunhan pissibang = the many PC-rooms of Yeouido], roughly equivalent to saying "Hey, there's internet-cafes around capitol hill" (see the other pictures there to understand what this means – most of the pictures are of the various inappropriate things the legislators do with their PCs during sessions).