+1 on the Macadamia nut farm. The nuts are delicious and they use every aspect of the nut commercially. The nut oil is sold to movie stars as a skin moisturizer, the honey produced from the nut flowers, and the flour ground from the nuts etc. Get him to show you the altered stationary bicycles the hired hands ride to grind the nuts.
Also if you have the legs for it, try climbing Volcan Acatenango. You will pass through 4 different ecosystems on the way to the 13,000'+ summit. Once on top, you can watch its sister volcan Fuego erupt. Quite a trip. Check first to make sure its safe...., sometimes it's a little frisky.
And the jade factories....... Ahhh, Antigua..., land of eternal spring!
Life is a story. Make yours worth telling.