Kanata, Kureha, and Noel pass a broken pillar with kanji etched into it. The kanji denotes that it was once a memorial or dedication.
Right before Kanata is inspired to blow her bugle, a signpost shows two other cities, Treize and Neuf in addition to Seize. In French, that would respond with thirteen, nine, and sixteen, respectively.
Regarding the villagers splashing each other with wine - it's most likely based on a real festival in Spain called the Haro Wine Festival, where everyone fills up various containers with wine and "attack" each other.
Kanata sees a "fish" figurine and reads the price as 10 yen and 25 sen. The sen is a subunit of yen (where 1 yen equals 100 sen) that, since 1953, is no longer in circulation.
The town of Seize is based on real world Cuenca, Spain.