In both kilometers and miles, what is the world's longest jetty or pier?

The world's longest "wooden pier" is Busselton jetty , Western Australia. It goes out for 2km.
https://en.m.wikipedia.org/wiki/Busselton_Jetty

The longest pier in the world is the Progreso Pier in Progreso Mexico, which is 4 miles, or 6.5 Kilometers long, and was built to allow cruise ship traffic in the Gulf of Mexico to call at the colonial town of Merida.
http://googlesightseeing.com/2008/05/20/the-worlds-longest-pier/
Side view:
http://www.panoramio.com/photo/1904451

The longest pier/jetty in the Southern Hemisphere is in Lucinda, Queensland, Australia. It is 3.57 miles, or 5.76 kilometers long. The Lucinda Jetty is technically a pier, as it is structure suspended above sea level, but unlike many piers it runs diagonally from the shore, so that its pilings do indeed provide a bit of a breakwater to the shoreline. It's a cross between a jetty and a pier. One could call it a "petty" if one was not afraid of being jeered, or a 'jier' if one were not afraid of petty remarks. It is used strictly to offload bulk sugar to waiting ships.
http://www.trekearth.com/gallery/Oceania/Australia/photo400565.htm

Pier vs. Jetty:
https://en.wikipedia.org/wiki/Pier
https://en.wikipedia.org/wiki/Jetty