No boats allowed in Amsterdam canals

To allow the ice layer in the canals to grow, the city of Amsterdam has forbidden all boats in a number of canals.

It does not happen very often that ice skating is possible on the canals in the centre of Amsterdam.
The last time ice-skating was possible, on the Keizersgracht canal, was in 1997.

Winters tend to be warmer in the last few decades. Also, it takes longer for the canals to freeze in the centre of a city than out in the country side.

This time, a number of canals are blocked for boats, in the west part of the canal area, including the entire Jordaan area.

Continuing frost is expected for the week to come, so pictures like below belong to the possibilities.