Melidoni Caves
The brochures says that Melidoni Caves are "a charming and mysterious place of destination travelers". Okay, awkward phrasing notwithstanding, here's my unbiased opinion on the Melidoni Caves. If you have to drive from Chania or Heraklion to Myrtos and you want to break up the drive a bit, why not plan a break at Melidoni Caves. It is not too far of a detour, not too expensive AND it's very cool inside so it's a great way to beat the heat.
That said, it's a relatively small cave and fairly sanitized (with lighting and explainer signs) all around. If you've done any spelunking before, this would probably be classified as a class 1 rapid. That said, the history is pretty interesting.
The cave has been known as the "sanctuary of Hermes" ever since a hymn honoring the god was found transcribed on one of the walls around 1445. Many peoples lived in or used the caves over the centuries, including for storage in the Late Neolithic pariod or for worship in the Bronze Age. But the story that carries the most impact is that of the 370 Cretan civilians who were locked in the cave and axphyxiated by the ruling Ottoman Turks in in 1824.
As the story goes, the Turkish soldiers closed up the opening that let in light and air, but when they opened it up again, the Christians inside were still alive. So they picked up wood, oil, chaff, alcohol, sulfur and anything else tha would burn and set fire to it. The smoke passed through the first chamber into the second snuffing out any life inside.
So not a feel good story to be sure. But interesting to contemplate as you silently wander the circular path inside the cave. The cave itself is carved out of limestone marbles that are around 200 million years old. The process of creating the cave took place over 3 phases that spanned millions of years.