Once upon a time there was a place where 300 hermits lived. They never had contact with each other and stuck to their caves and their ascetic, solitary lives. But they did meet one day a year, in a cave where each hermit chose the same rock to sit on year after year. If, in a given year, a previously occupied rock was unoccupied, the other hermits would know that its owner had died, and arrange to have him buried.
That place is the Agiofarango Gorge, or Gorge of the Saints. It's on Crete's south coast, not far east of Matala, and ends at a very pleasant beach on the Sea of Libya. The part of the gorge tourists generally visit is not very long; it's about a 3 km walk if you start at the trailhead which is reachable by hiking or driving a gravel road from Matala. You can start further away from the mouth of the gorge, higher up in the hills, near the Monastery of Odigitrias, but be advised that once you reach the beach, the only way back is to retrace your steps, so that a 3 km walk is really a 6 km walk. The beach has 0 facilities, and no dock. Any boats stopping by are private craft on a day trip which drop their anchors offshore. Generally speaking, this part of Crete is mountainous and sparsely populated.
The gorge itself is narrow, with interesting rock formations along its entire length. You'll pass a monastery and a couple of churches. It is as quiet, remote, and vegetation-free a place as you'll find on Crete. The chief plants growing in the gorge are oleanders and a few scrubby evergreens. There is no rain for several months out of the year. The gorge itself, being a dry riverbed, channels water during the winter rainy season.
Because the walls are often sheer, the gorge has become a favorite of rock climbers. The beach at its end is pebble and sand, a small cove hugged by the same sheer rock formations encountered during the hike. The waters of the sea are clear, and there's a lot of exploring that can be done among the rock formations where they meet the sea, provided you pack a mask and snorkel.
A word of advice: because of the lack of facilities and rather sparse shade, it would be a good idea to bring plenty of water.