Sibenik is a very typicall mediterranean city with lots of short and very narrow streets which goes up and down in a kind of a confusion way.
What you need to know when strolling around is that you cannot be lost here. In case you find yourself lost, just turn down in the direction of the coast and you'll be saved.
DO travel with strong painkillers, as these countries do not always have drugs available to the local doctors. Our friend had broken his hip and my aspirin/codeine was less than useless. The doctor who saw him had no painkillers and the ambulance was broken! Things may be better now, but better to be on the safe side.