The cache is usually packed with swag so you're welcome to take something even if you don't leave anything. Just pay it forward and leave something cool in another cache. :)
It is my opinion that there aren't enough obnoxiously large caches around. Therefore, I planted one in a suburban yard. The yard is not fenced in and you should have no problem getting to the cache. Yes, it's okay to come into the yard to check out the cache. :) Though you might get the occasional awkward wave from me and my fam, you'll otherwise have no issues! In the decade I've had this cache, visitors have been nothing but awesome and respectful, so it remains!
THINGS YOU CAN PUT IN THIS CACHE (because they fit): Tshirts, hats, mugs... In fact, I have been known to put some of these things in the cache on occasion. Just put your cool stuff in ziplocs in case of leaks! (Better to just place items that will not be permanently damaged by moisture anyway.) I tend to put a lot of silica packets in here to keep it a bit dryer. If you notice a lot of moisture in the cache, please log it so I can go dry everything out! Happy caching!