Inside tip · Margaret River

Busselton Jetty, the Southern Hemisphere's longest timber-piled jetty, is how long?

Answer: About 1.8km

It's 1.841km long over Geographe Bay, and home to one of six underwater observatories in the world.

1.841km · train rides and observatory tours all year

The heritage-listed jetty runs over protected waters. Observatory tours and jetty train rides can be booked all year, weather permitting, and the train is solar-powered.