The naumachia (in Latin naumachia, from the Ancient Greek ναυμαχία/naumachía, literally “naval combat”) in the Ancient Roman world referred to both the staging of naval battles as mass entertainment and the basin (or more broadly, the complex) in which this took place….
http://en.wikipedia.org/wiki/Naumachia
Or what about diving horses? [video:youtube:r8vIjuIeQpM]
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