This is the 13018th most frequent Korean word.
동대문구를
"동대문구를" is the accusative form of "Dongdaemun-gu," meaning "Dongdaemun District" in Seoul, South Korea.
In this sentence, '동대문구를' refers to the district 'Dongdaemun-gu', and the object marker '를' indicates that the district is the direct object of the verb '방문하다' ('to visit').
동대문구를 방문해서 맛있는 음식을 먹었습니다.
I visited Dongdaemun-gu and ate delicious food.
Here, '동대문구를' again represents 'Dongdaemun-gu', the district receiving the action of the verb '산책하다' ('to take a walk').
제가 동대문구를 자주 산책합니다.
I often take walks in Dongdaemun-gu.
In this sentence, '동대문구를' serves as the object of the verb '알다' ('to know'), as utilized by '아는', describing the friend's association with the district.