It is designed to expand Monaco into the sea by doubling the size of its port.
The dock, thought to be the biggest of its kind in the world, weighs 160,000 tonnes and is 350 metres long.
World's largest dock
160,000 tonnes
350 metres long
30 metres wide
20 metres
high
The semi-floating wharf will make it possible, in particular, for luxury cruise liners to dock in the port.
It will also double the docking capacity at La Condamine Port and protect it from the swell.
The dock was tugged in after a 13-day voyage from its Spanish maker in Algeciras.
Site managers estimate they will need 10 days to secure the concrete structure to the rest of the port with a 700-tonne steel stirrup and other anchors attaching it to the seabed.
The delicate task will be achieved with a laser-guidance system.
When it is finished, the wharf will boast four levels, a storage area for boats and a multi-storey car park as well as several shops and restaurants.
The project's total cost already comes to 150 million euros, and is due to be completed by 2005, but the wharf is intended to last at least 100 years.