These steep sides were caused by movement between two Tectonic Plates - the American Plate and the Eurasian Plate. The gap in the middle has a long history of human habitation. The Vikings used to hold their councils here and market stalls used to line the base of each wall. Small mounds can still be seen along the bottom of the walls.
Just sent a link to your album to a friend who is heading to Iceland on Tuesday. Your photos are wonderful and capture the beauty of the country -- enjoying them a lot.
@olivetreeann Hi Ann - yes - and it seemed weird to know that the chunk of Earth holding up America was on one side and the chunk holding up Eurasia was on the other!
@golftragic Hi Marnie - I knew waht a rift valley was from eaching junior science - but I had no real idea what to expect. The walls were actually a lot steeper than this but I put this one up because it showed part of the glacier in the back (Atleast I think it was a glacier - poor memory!! :) )
@taffy Thanks Taffy - I'm so pleased you've enjoyed them. I'm going to post a second lot of Iceland images today (there was so many stunning sights there that it was impossible to whittle them down to just 4) We hired a car and did 2 day tours - one to the Golden Circle and one to the South Coast as far as Vik. They are both relatively easy days from Reykjvik and very well signposted. It was much, much cheaper than doing a tour - and you're not stuck in a big crowd. We got a tour booklet and just googled the places they were going to and followed their path - it worked well. I'm sure your friend will have a marvellous time. P.S. If they are cooking for themselves tell them to buy some Icelandic lamb - it is heavenly!! :)