why aren't there more 13K races?

[lauradi7dw]

A third-marathon makes as much sense as a half-marathon. I found a few online, but none nearby (although there was a 15k race in NH yesterday). The former Disney Tower of Terror 13K has been changed to 10 miles. While I was browsing, I was hit again with how little knowledge of geography I have. For no good reason, I would have expected the Hong Kong area to be flat, but clearly I'm totally wrong
http://www.actionasiaevents.com/attachments/146_MapSaiKungsprint2012.pdf