  International scientific collaboration, a fundamental phenomenon of science,
has been studied from several perspectives for decades. In the spatial aspect
of science of science, cities have been considered by their publication output
or by their citation impact. In this visualization, we go beyond these
well-known approaches and map international scientific collaboration patterns
of the most prominent science hubs considering both the quantity and the impact
of papers produced in the collaboration. The analysis involves 245 cities and
the collaboration matrix contains a total number of 7,718 international
collaboration links. Results show that US-Europe co-publication links are more
efficient in terms of producing highly cited papers than those international
links that Asian cities have built in scientific collaboration.
