I had a good look at the JNA base and the tunnels under it near Lumbarda a couple of years ago. It’s not a huge network but they’re quite interesting and lead up to several gun emplacements carved into the rock. The tunnels near to Pomena on Mljet are much more extensive. There are boxes for artillery shells lying about the place, the guns are still there and it’s all in very good condition. Does anyone know what else there is of this kind on Korcula? I get the impression there is stuff up past Vela Luka but I haven’t had a chance to go look yet.