Is there a mobile phone signal inside Nil Diya Pokuna?

Inside the Nil Diya Pokuna cave system, there is pretty much zero mobile phone reception. As soon as you go down a couple of metres after the entrance, the network drops completely because of the thick layers of solid limestone plus earth that block the signal in a very direct way.

This full absence of any communication infrastructure means you really have to go with a registered guide. Before you start the hike, visitors should tell someone at the hotel about what route they plan to take and the expected return time, so authorities can be notified if you do not show up when you said you would.