United Kingdom, Greece, Denmark, Sweden
Samaria Gorge. 16km long, 1,250 meters (almost 4,000 feet) of elevation loss, plus 2km more to the village of Agia Roumeli on the shore. The "Iron Gates", although properly known as the Portes by the locals ("Gates"), are only 4 meters (13 feet) wide and almost 500 meters (1,650+ feet) high-- among narrowest in the world. Take a ferry back to Sogia and a coach from there back to Hania.
Ok, the details aside... Samaria Gorge is beautiful. It's not that difficult of a hike if you're in reasonable shape, and it's pretty as hell as you descend, cross the rock fields, through the gates. Just remember, even though it's downhill, it's still a 10 mile hike, so pack water and an appreciation for nature. I've never hiked anything quite like it. Please don't wuss out and hike the lazy way from the ocean side, you're missing out if you do!
Ended the day stopping by another village on the way back to Hania, then back to Cafe Crete to see how a lyre is actually carved. Oh yes, Cretian graviera cheese is yummy.