Westvleteren is hard to get as it is only sold at the brewery Abbey of Saint Sixtus (Westvleteren, Belgium) itself. So first you have to call their beer line to make an appointment. When picking up your limited order, they note down your licence plate number to make sure you don’t come regularly (once every two months is Ok).
The brewery was founded in 1838 and continued brewing during WW I & II. Westvleteren has won several first places with their outstanding beer. Something to put on your bucket list!