For information about all of our own Galaxy's globular star clusters, I refer all of you to the catalog of Milky Way globular star clusters by William E. Harris at:
http://www.physics.mcmaster.ca/Globular
Harris has specialized in globular clusters for all of his professional life, and I believe that he is still keeping this list of globulars (and their properties) updated.
In this catalog you will find many nuggets of information;
for instance, the fact that NGC 6522 and NGC 6528 are almost the very nearest known globular clusters to the very centre of our galaxy. They sit well within the central bulge component of our galaxy at only 0.6 kiloparsecs (1950 light years) from the very centre of the Milky Way galaxy.
When we view this pair of globulars, we have a "porthole view" into the centralmost part of our galaxy, untroubled by the heavy dimming of light (from interstellar dust) that afflicts many fields in the direction of the centre of our galaxy.
[ If you have any trouble understanding some of this catalog data, with its usual arcane symbols and jargon, just drop a line to "yours truly"(madbadgalaxyman), as I am expert at deciphering numerical data in catalogues. ]