The Danube's freezing is just one of many severe winter events in the continent this year.
The Danube flows through 10 countries, so precise records of its last freezing are not easy to come by. But an obvious reason for this year's freeze is the teeth-chattering cold.
All navigation on the Danube, which serves as a border between Bulgaria and Romania, has been banned with ships sheltered from the ice in ports and river channels.
