Nagoya Dome is the city's big covered stadium and the home of the Chunichi Dragons. Baseball in Japan is loud, ritualised, and much more communal than a casual glance at the field suggests, with organised cheering sections, songs, food, and a steady hum of crowd choreography.
It is worth considering if the Dragons are playing while you are in town, especially if you have never seen Japanese baseball. Outside an event it is not a major sightseeing stop, but on game days it shows a side of Nagoya that castles and museums cannot.