This is the 9055th most frequent Russian word.
ростовская
"Rostovskaya" refers to something related to Rostov, a city or region in Russia.
In this sentence, 'ростовская' modifies 'область' (region), indicating that the region is related to Rostov.
Ростовская область славится своими природными красотами.
The Rostov region is famous for its natural beauty.
Here, 'ростовская' serves as an adjective for 'гостиница' (hotel), specifying that the hotel is associated with Rostov.
Ростовская гостиница находится недалеко от центральной площади.
The Rostov hotel is located near the central square.
In this example, 'ростовской' modifies 'школе' (school), showing that the school is in Rostov or affiliated with the Rostov area.