Backyard Pullup - Rope Climbing structures

I want to set up a structure in my backyard for pullups and a rope climb as well.  There are lots of resources available on the web to get ideas from. Here are a few:

Steel Structure for mostly pullups and dips

Got distracted and thought this might be fun to build as well:

Backyard Rope Zip Line Video

A related how to:
Kid Zip line out of rope how to

 Back to another training tower video:
Crossfit Training Tower

This might be the best looking structure as it looks like a Garden Arbor /Trellis/Pergola

Simple enough but doesnt look the least bit stable Chin Up Pullup Bar