This is the 2673rd most frequent Russian word.
ярмарке
"Ярмарке" (ярмарка) - "fair" or "marketplace."
In this sentence, 'ярмарке' is in the prepositional case, indicating the location (at the fair).
На ярмарке продавались разнообразные товары.
Various goods were being sold at the fair.
Here, 'ярмарку' is in the accusative case, showing the destination (to the fair).
Мы приехали на ярмарку, чтобы купить свежие овощи.
We arrived at the fair to buy fresh vegetables.
Once again, 'ярмарке' is in the prepositional case, specifying the location (at the fair).