Kopi joss
Indonesia
This tourist tick-off was invented in Yogyakarta in the 60s by a coffee stall vendor called Mr Man, who remedied his stomach ache by dropping hot coal in his cuppa - it's believed that the charcoal neutralises coffee's acidity while giving the drink a smack of burnt sugar. The name "kopi joss" comes from the sizzling sound made when the coal is dropped in.