Toyohashi sits in eastern Aichi, between Nagoya and Hamamatsu, where the old Tokaido road met Mikawa Bay. It is not a showpiece city, but it rewards a spare day in central Honshu with castle remains, a surviving Edo post-town inn, and one of Japan's few remaining streetcar systems.
The strongest stop is Futagawa-shuku Honjin Museum, built around one of the last surviving honjin inns from the old Tokaido. In the centre of town, Yoshida Castle and Toyohashi Park give you stone walls, a reconstructed turret, and a good place to understand the city's older role as a castle town.
Toyohashi also has an easy, slightly old-fashioned rhythm. Ride the tram from the station toward the castle district, then spend the afternoon at Non Hoi Park, a large zoo, botanical garden, and natural-history museum rolled into one. It is the sort of place that works best when you are already in Nagoya or crossing central Honshu and want a day that is quieter than the big-city circuit.