Seeing as the UK monsoon season (summer) is fast approaching I am in need of things I can do outside either in the pouring rain or on an overcast day when rain is probable.

The only restrictions on what I can do is my medium /out/ skill level and the very limited freedoms of the UK, so camping and fires are pretty much out of the question (legally) but I'm open to all suggestions.

>TL;DR, what to do outside in the UK when its probably going to rain