I have Arkham Horror and played through a few times by myself so I can teach other people.
However I can't seem to find in the rule book or a quick search in these forums what the heck the activity markers are for. I see they appear from mythos cards, but I am unable to find what exactly they mean. Do monsters spawn there? Gates? Or are there cards I just haven't drawn that specify what happens at activity markers?
Also I can't seem to find this in the rules or explicitly explained in the forums. If you do not leave the location/street you're in does that mean you are just in a sort of stasis and do not have to enter combat with a monster who is at the same location/street?