[gerhardi]

I wonder if there are clusters where distance between neighbouring stars are much less than with Sun and Proxima Centauri. Would these locations provide better opportunities for space faring civilizations to reach other star systems?

[nyrath]

I'm no expert but I think the answer is "No", due to other problems.

Distances are closer in Globular Clusters. Alas, those are "metal poor", so the only planets are gas giants like Jupiter.

Distances are closer in Open Galactic Clusters like the Pleiades. Unfortunately those cluster tend to disperse. By the time a space faring civilization has evolved, the stars are no longer close.

Distances are closer in the Galactic Core. Unfortunately that is a high radiation environment due to Sagitarius A* (the mega-black hole at the center of the galaxy_ and all the nebulae the hole is dragging in.

Short answer: places where the distance between stars is closer are unlikely to have space faring civilizations.

Of course there is always Zeta Reticuli A and B.