  There is an increasing trend of people leaving digital traces through social
media. This reality opens new horizons for urban studies. With this kind of
data, researchers and urban planners can detect many aspects of how people live
in cities and can also suggest how to transform cities into more efficient and
smarter places to live in. In particular, their digital trails can be used to
investigate tastes of individuals, and what attracts them to live in a
particular city or to spend their vacation there. In this paper we propose an
unconventional way to study how people experience the city, using information
from geotagged photographs that people take at different locations. We compare
the spatial behavior of residents and tourists in 10 most photographed cities
all around the world. The study was conducted on both a global and local level.
On the global scale we analyze the 10 most photographed cities and measure how
attractive each city is for people visiting it from other cities within the
same country or from abroad. For the purpose of our analysis we construct the
users mobility network and measure the strength of the links between each pair
of cities as a level of attraction of people living in one city (i.e., origin)
to the other city (i.e., destination). On the local level we study the spatial
distribution of user activity and identify the photographed hotspots inside
each city. The proposed methodology and the results of our study are a low cost
mean to characterize a touristic activity within a certain location and can
help in urban organization to strengthen their touristic potential.
