So, here are two things I (used to) enjoy doing on vacation: sleeping in, lying on a couch all day reading a book. I don't think I've done either of those things on vacation since my son was born almost a decade ago. If you haven't already seen it, you might enjoy this post --
http://www.huffingtonpost.com/m-blazoned/vacation-or-trip-a-helpful-guide-for-parents_b_7789310.html .
That said, no idea how much you enjoy staycations, but I'd certainly vacation with a 6-month old, and there are noticeable advantages to traveling with kids before they become self-propelled as opposed to afterward. With a six-month old, I'd skip the frame packs (though they can be wonderful with bigger kids) and go for either a sling pouch (my choice, but not the usual favorite) or something along the lines of an Ergo/Beco and hike as much as you want. But whatever you consider, buy (or borrow) one first and try it at home -- people have strong opinions about what constitutes a "good" or "bad" carrier and preferences seem to be pretty idiosyncratic.
Six months is really too little for the kid to have many opinions about what you're doing, which is both a good and a bad thing. No need to seek out kid-friendly attractions (as long as you avoid kid-unfriendly ones), but not much guidance on what to do. I do remember both visiting the beach (not in the full heat of the summer, maybe May) and flying to Oregon (to visit family) when my son was in the 6-8 month range. At the beach we sat and played in the sand (and water, but not the ocean proper -- tidal pools), and in Oregon we hiked, went out to dinner and played pool (friendly, smoke-free billiards hall, quiet times), and went to a llama farm, I forget what else.
Not strictly relevant to 6-months, but I will say that vacation spots, hikes, etc., with water features (lakes, streams, pools, doesn't really matter) have become a much bigger part of my planning since having a kid. "Let's go for a walk in the woods!" = pretty uninteresting to my son. "Let's walk to a lake and throw rocks/sticks/sand in the water!" = wildly exciting.