Crete has many gorges of which Samaria is the most famous and biggest. It's a big walk (all downhill) which took myself & husband, who are pretty active, 5 hours at a reasonable pace. It is about 17km from the entrance to arrive in the village at the other end and sunglasses/high factor sunscreen/a hat and some sort of snack are essential between June-September I would imagine. I walked with no problems in trail running shoes. There are basic toilets throughout the gorge and plenty of fresh water available to fill up water bottles. The gorge is stunning, the scenery well worth the effort. Take swimming kit for a dip in the sea at the end - very refreshing!The village at the end is lovely and there are plenty of tavernas to get a meal. The ferry out is always pretty much packed but it's an enjoyable sail round the coast. Really enjoyed it.