same here…66.249.78.1 – – [21/Dec/2015:17:52:23 +0100] “GET /amp/ HTTP/1.1” 404 4002 “-” “Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)”
and other pages can be access with any stuff after blog_post/amp/blaablaa <- 200
using nginx here