How do they plant those large poles into the lagoon in Venice?

Question

You know the ones. The boats use them for route markers and for mooring.

It seems to me to be quite a technical feat, but it has been done for 500 years.
In fact, large parts of the city are built on poles such as these.

Nice answers, thank you all, and I have spent some months in Venice, but I still need to know, what equipment do they use to drive the poles in, especially on the open water: do they stand on a raft, and use a giant hammer, for example?

Answer 1

Very carefully

Answer 2

The city is built on tightly packed wooden piles or stakes which have nothing to do with the poles in the Venice lagoon. Have a look at my previous answers for more information on how houses were built in Venice.

Answer 3

Buildings are constructed on closely spaced wood piles (under water, in the absence of oxygen, wood does not decay) which penetrate alternating layers of clay and sand. Most of these piles are still intact after centuries of submersion. The foundations rest on the piles, and buildings of brick or stone sit above these footings. The buildings are often threatened by flood tides pushing in from the Adriatic between autumn and early spring.

Answer 4

I live in Venice, so you can trust on me! :-)
They plant them on the ground, under the sea! And also the houses are based on the ground! In Venice the sea is not deep and so you can reach the ground in few metres! :-)

Answer 5

There are no lagoons in Venice... only canals and the bay.