Watch water burn at Arçivan village! What you see is a little drinking fountain beneath a concrete pergola, but the water that bubbles forth is made ‘flammable’ by partly dissolved methane. Bring your own matches – the flames blow out fairly rapidly and locals come to collect the water for drinking rather than for pyrotechnics.
The spring is 9km north of Astara beside the old road to Lənkəran. You'll need to pay a little extra for taxis to come this way as it is far quicker and easier for them to drive via the new highway.