You should definetely get to see Vikos gorge at Oxya when visiting Zagorochoria. A few kilometers after the village Monodendri you will see a sign for Oxya. Park your car there and follow the path.
It is truly one of the finest and most spectacular viewpoints of the canyon. At this point, you are in the middle of the gorge and just across is the Great Pit, an offshoot of the gorge of Vikos.
The gorge has 12km length, a depth of over 900 meters and 1,100 meters width. For these dimensions it was recorded in the Guinness record as the deepest canyon in the world in proportion to its width.
You can also cross Vikos gorge while rafting the river Voidomatis and its crystal waters.