They're dirty, sometimes smelly in the summer and stretch for kilometres … canals, don't you just love them? John Scott reports.
Venice of the North
Amsterdam is not known as the Venice of the North for nothing.
In fact, Amsterdam consists of 90 islands, separated by 100 kilometres of canals linked by around 1,000 bridges.
The city developed around a dam in the Amstel River at the end of the 12th Century, hence the name Amsterdam. The first canals were built in the 14th Century, with later canals such as the Singel forming the defensive moat for the old city walls.
The bigger canals of the Herengracht, named after the men that invested in it, the Keizersgracht, after the Roman Emperor Mazimillian, and Prinsengracht, named after William, the Prince of Orange, were not built until the early 17th Century.
These were constructed during the city's golden age - when Amsterdam was the trading capital of the world - and when the city needed to expand to house its exploding population.
The rich middle classes built their houses overlooking the three bigger canals while poorer people were pushed into the surrounding side streets.
Canals as life blood
Some of the canals were already there in the form of ditches, particularly those around the Jordaan area.
But in view of Netherlands' wet climate and low lying geography, most of the inner circle of canals in the old historical centre were dug up so that the mud could be used to build up the land, acting as a barrier to both enemies and the sea.
The canals themselves were also part of this defence mechanism.
"The inner circles of canals used the materials dredged up to raise the land. Obviously the other reason is for the transportation of goods and having warehouses on the canals," a policy advisor for Amsterdam's DWR department, which is responsible for the canals, Eilard Jacobs, said.
Warehouses on the sides of the canals were used to store goods arriving or being dispatched on the river Amstel and into the Ij to the north of the city.
Now the canals are largely maintained to peg back the sea and surrounding marsh.
Threat from modernisation
But with the rapid industrialisation of Europe in the 19th Century, city planners looked for more space. This development threatened the canals and many were filled in, streets were widened and bridges lowered as part of a modernisation drive.
Nieuwezijds Achterburgwal, the present Spuistraat, and Nieuwezijds Voorburgwal were filled in the latter part of the century, while Rokin was filled in during the 1930s.
This trend has now reversed, with many of the canals being recognised as sites of historic interest.
I have always imagined that the first thing you should do having fallen into a canal (besides getting out) is to get your stomach pumped and have any number of hepatitis and other inoculations.
But Jacobs says this is no longer necessary.
If you think the canals can be smelly now on that rare warm Dutch day, imagine a hundred years or so ago when the canals were actually used as the main means of sewage disposal. At that time, Amsterdam used the rising and falling tides to clear the waste.
But with the Ij being damned and now turned into a lake and with various other damns in place along the Amstel, there is little in the way of tidal movement. The canals are pumped twice a week during the winter and four times a week during the summer to keep them clean.
Surprisingly, the canals are only up to two meters deep. The reason you can't see the bottom of them is because of the high levels of silt in the water, often churned by the coming and goings of various barges.
The canals have to be dredged once every ten years.
Dredging up the odd dead body
"You get weapons, many cycles and the odd dead body," Jacobs said on some of the things found during dredging.
According to the Time Out guide to Amsterdam, 52 corpses are pulled out of the canal every year. The vast majority of those pulled out are vagrants, who have usually fallen in to the canal in an inebriated state.
This could go some way to explain why Amsterdam has open-air pissoirs in certain parts of the city and why on a Friday and Saturday night, hundreds of mobile pissoirs spring up around the main tourist squares.
According to the police, around 50 people are murdered on average in the city every year. So if the Time Out figures are correct - and I couldn't get confirmation from any official agency - then the typical Amsterdam inhabitant has more chance of drowning in a canal than being murdered, a sobering thought.
In addition to the corpses, around 10,000 bikes and 100,000 tonnes of sludge are lifted from the canals every year.
Whatever might lurk in their brown depths, the canals remain the best way to see the city and a variety of canal cruise companies offer tours of the city at reasonable rates.
Just be careful not to fall in.
Subject: Amsterdam canals