This is the 11865th most frequent Polish word.
krośnieńskiej
The word "krośnieńskiej" is the genitive or locative singular feminine form of an adjective in Polish, meaning "of/from Krosno" or "related to Krosno," a city in Poland, or a place/system named similarly.
In this sentence, 'Krośnieńskiej' is used as an adjective derived from the name Krosno, referring to something related to that location, specifically a theater.
We visited the Krośnieńskiej Theater last weekend.
Odwiedziliśmy Teatr Krośnieńskiej w zeszły weekend.
Here, 'Krośnieńskiej' qualifies the word 'architecture', linking the architectural style or features to Krosno.
The Krośnieńskiej architecture is truly remarkable.
Architektura Krośnieńskiej jest naprawdę niezwykła.
In this context, 'Krośnieńskiej' describes the artistic community as being from or associated with Krosno.