As an aside to the gorge issue, anybody who is relatively new to Crete should be aware that they need to be extra careful on the roads over the next few days. The population of Crete, plus about the same number again of tourists, have spent the summer months carefully laying down a coating of rubber, oil and diesel on all road surfaces. When you add copious quantities of water to that for the first time it forms a very good imitation of a skid pan. Don't expect your brakes to slow you as quickly as normal. There will be plenty of rear end shunts over the next few days. Gradually the rain will clean the roads and everything will go back to normal. While the problem exists in northern Europe it isn't usually as bad as here, because there is more regular rainfall through the summer period, so anybody who has moved here from northern Europe might get a bit of a shock.
PS Especially bad on two wheels.