If you only have time to do one thing whilst you're in Santorini, it has to be the walk along the Caldera from Fira to Oia. The hike is 12 kilometres long and takes betwee 2 and 4 hours depending on how many times you stop for photographs, passing through the 2 villages of Firostefani and Imerovigli are some of the most dramatic scenery from the cliff edges across the Aegean.
The hike begins in the capital of Santorini, Fira, at the cable car station near the Catholic cathedral, you the follow the cobbled footpath up along the caldera towards the village of Firostefani and is normally very busy with tourists. Once you're in Firostefani you keep on the path straight through the village where there are plenty of cafes and restaurants looking over the caldera.
After leaving Firostefani you join the trail again to the village of Imerovigli which is 3 km away from Fira, at this point I was an hour into the walk. Imerovigli is at the highest point of the Caldera so you have great views of the vocano as well as both Fira and Oia. It is also the last village you will pass through before you reach Oia, so make use of the bars, shops and cafes in Imerovigli and stock up on water. You come off the trail in Imerovigli and have to make your way through the narrow streets past Skaros rock.
To rejoin the trail you have to come out of Imerovigli near to the main road and a square, walk about 100 metres and rejoin the trail. After leaving Imerovigli the trail becomes a lot more rough and more difficult as it climbs up to the church of. From here you have great views of both sides of the island and even the airport. At the top of the path is another church, from here the path goes downhill for a good distance.
The next part of the hike becomes a lot more difficult as you now join a a sandy track that winds around the Caldera up and then down, out of the whole hike I would say this part is the most dangerous as the volcanic sand isn't that steady under your feet and the path is only about a metre wide in places. Once you come down from the track you join the main road between Fira and oia, where you turn left and follow the road for about 250 m and join the donkey trail again.
Just before you join the trail again and leave the main road there is a cantina where you can by drinks and food, this is good place to restock on water as there is nothing else between you and Oia and you still have about 2 hours walking yet to do.
The next part of the hike is all up hill and probably the hardest part as the trail is now just a rocky dirt track, but the views make it all worthwhile. At the top of the climb is a and church and a small square, from here it is all downhill to Oia which you have a great view of from the church as well Imerovigli. Looking back to Imerovigli and the Caldera you get a true sense of the distance you have walked and the beauty of Santorini and the Caldera.
The walk down into Oia is the most satisfactory part of the hike as the dirt track slowly changes to a cobbled path then to a proper road. You are in Oia, Santorini's most beautiful village with its bars, cafes, shops and restaurants and you can finally have your hard earned cold beer or coke depending on your taste.
The hike is 12 Km and over some rough terrain, so bear this in mind before you do the walk. It is best to do the walk early morning before the sun gets too hot as there are no trees and little shelter, so take plenty of water.