The big wave occurred because of the collapse of part of the glacier, which is located in the south-east of Iceland. At the time, a dozen tourists were on the shore.
The nature-watchers had to evacuate urgently to avoid being washed into the icy waters of the North Atlantic.
"They were not scared, but rather very excited," said Stephan Mantler, who works for the travel company Háfjall, according to Iceland Monitor.