If you are in HK and you want to get out of:
A. The Heat
B. The Rain
I suggest a museum day. My second full day was my museum day, although I lost interest after the Museum of Art, which was excellent. Their exhibition of Qing and Ming objets d'art had one of the best exhibition guides I've ever seen. Throughout the exhibit were curio cards with a picture of one of the pieces on the front and an explanation of the particular aspect of this era's masterworks it embodied on the back. They made a brilliant souvenir, and, since I went on Wednesday, free.
I was also happy to find some street art in Hong Kong. Actually, since it was so bloody hot and I didn't feel like getting heat rash in the name of a school trip that probably won't come here, I didn't end up chasing down any galleries. That made finding street art a welcome boon. I was especially pleased to see yarn bombing on this hand rail. I've never seen yarn bombing anywhere other than the internet. To see it in the actual world made it a real thing.
For a long time, Hong Kong's street art was the domain of one man, the self-proclaimed King of Kowloon. Since his death in 2007 there has been public pressure to protect his legacy, but I was pleased to see that other artists were continuing the tradition - perhaps not in his medium, because he was a calligrapher, but at least were making public works of art.
And speaking of being done with Hong Kong, that's all, folks.