It is nice to go and wonder around in the old town of Stockholm called Gamle Stan. It has many nice old buildings and small streets which can keep you entertained for quite a while considering how small the old town is.
One particular street is fun to walk through it is the small alley called Mårten Tratzigs Gränd. The street is quite steep and very narrow. It is so narrow that virtually everybody can reach from side to side unless it is a toddler.
The width of the alley at its narrowest part is only about 90 centimeters or 3 feet so you don’t have to stretch the arms to reach both sides of the alley at the same time.
The street is pretty popular so if you want a picture without too many other tourists in the picture you might have to wait for a while.