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There are a lot of “instant gratification” traditional caches in the Vienna and surrounding areas where the cache is a film canister or a petling (either magnetic or non-magnetic) hidden in a phonebox. Similarly there are a lot of mystery caches that lead to phonebox. As a form of variety there are some phoneboxes that have been converted into open bookshelves. If you are afraid of spiders, some phonebox caches might require you to overcome your fear of spiders to get the cache. It is also worth bearing in mind that caches usually have to be 161 metres apart, but a greater (500m IIRC) distance applies for caches in the same kind. I tried to place one in a phonebox in the 7th district and was told that a mystery cache was in a phonebox less than 500m away…