Amsterdam - Canals

Science in Amsterdam

,If you decide to travel to Amsterdam you may enjoy seeing
 something you have never experienced 

!!!No, I'm not talking about drugs
.Has you might see there are lots of things to do in the city as a for tourist
but if you want see also something different to in the north part of the city

for example a little bit of free science

How do boats pass trough the canals

?almost without changing the level of the water in the canal