43115
In 1285 , the knights built a stone fortress on the site , which is today known as Rēzekne castle ruins , to serve as a border post on their eastern frontier .
 Rēzekne
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Rēzekne