The Magaliesberg Major Traverse starts at Hartebeesport Dam Wall and traverses incredibly tough terrain for 77.49km all the way to Olifantsnek Dam Wall.  It has been done by hikers, but was first completed in FKT fashion April 30 - May 1, 2016, by Terence Vrugtman and Jason Gradwell, in a total time of 24h28m14s.

This is a Premier Route. To claim an FKT on this route, you must meet a high standard of documentation and verification. See details here: https://fastestknowntime.com/premier-routes.

The following description is taken from hikingsouthafrica.co.za/drakensberg-grand-traverse which is a thorough resource for those interested in completing this route.

Grant Strugnell posted this unusual FKT route:

The Hume and Hovell Walking Track stretches over 440km between Yass and Albury, in New South Wales, Australia.

The track allows walkers to rediscover the route of explorers Hamilton Hume and William Hovell on their expedition to Port Phillip in 1824.

Mt Taranaki is a popular mountain hike in New Zealand's Egmont National Park.  There are many FKTs on Taranaki, and even a website devoted to recording these:  https://taranakispeedrecords.wordpress.com/