Visited: June 21, 2023. The queue (line) to get in was torturous, it wrapped around the building and into the bus parking area. There were several bus loads of cruise ship passengers and no shade until the last ten meters before the ticket desk. Tip: Bring a sun shade umbrella if possible and consider a bottle of water for the queue as mandatory. Also, if you find a day when the cruise ships don't come to Kefalonia you will probably have a much better experience. It would be nice if the operators extended the shading during the busy season, we were here at the start of the season, way before it gets really busy, and were in the queue for at least 40 minutes before getting under the shade. In the cave the temperature drops quickly. the deeper you traverse the tunnel the cooler it gets. At the end of the tunnel is the lake where you are taken onto a boat and guided across the lake and around the small island with a group of 8 to 16 people plus the boat pilot. The trip across the lake and around the remains of the island is about ten minutes from the time every is seated to the time you arrive back at the 'dock'. The underground lake was visually stunning. You will probably have seen images of it on Google but it is really worth experiencing in person (keep in mind the cautions from the start of this review), you get the smells, sounds, feel, and spectacular visuals of which photos only show you a small slice. History & mythology: The cave has an interesting history that includes being a place of worship for the God Pan, the God of shepherds, flocks, open spaces, and sex. Archaeologists found evidence of worship on the island in the cave after the earthquake of 1953. The boat pilot spent time chatting and telling us some interesting facts about the cave as it is now, but what we really wanted was to hear about the history and mythology surrounding the cave.