This site will tell us more. . .
part of this exhibition. There are currently over 40 individual, unique large-scale sculptures, mostly horses, and the exhibition will grow to 100 by the time it culminates, after stops in Corinth, Paris, Istanbul, and Venice, in Mexico City 2017.
This one in The Guardian is not too long but gives a good sense of Aceves' goals. If you have the good fortune to be in Rome between now and January, I would urge you to take advantage of this opportunity to spend time with some magnificent sculptures -- or, if you're visiting any of the other cities with tour dates to come, you might want to research the possibilities for viewing there.