Hong Kong's Kai Tak airport closed in 1998. But while it was open it had the most
challenging approach in the world for airline pilots. The Checkerboard
Approach to Runway 13.
An Instrument Guidance System (IGS), an ILS-type signal, defined the final approach path. But it was offset from the runway heading by 47 degrees! One then had to follow a curving light path to the runway.
More daunting, a hill directly in the IGS approach path awaited those who did not turn onto final soon enough!
A checkerboard marked that hill.
You can download a video made by Charlie of the approach here.