I love this backpack!  It was great for our trip to Europe, because you can put your water bottle in the side pouch where it is accessible, and lots of different pockets inside the top and main pouches that each have zippers.  Yet the main pouch has enough room to stuff a puffer jacket into it.  On the opposite side from the open pouch is a zippered long narrow pouch.  I put my umbrella and my selfie stick in this pouch, because I didn't need it as often.  In European cities there are lots of pickpockets, and anything not zipped and out of sight, is usually stolen when in crowds.  Sure enough, the water bottle was out in the open, and it disappeared.  But I didn't use an expensive one, that would be missed, so it didn't matter.  If you are in the states, and using this backpack for recreation or school, this is something that isn't an issue, and it's nice to be able to access your water frequently, so I'm glad it has this open pocket.  It worked great as a purse in Europe!  I also liked that it was slashproof, and that the two main zippers have locks that aren't hard to open, but awkward enough that you would notice if someone tried to get it open.