This is the 3061st most frequent Japanese word.
ロサンゼルス
Los Angeles.
In this sentence, 'ロサンゼルス' serves as the subject of the sentence describing the location of the city.
ロサンゼルスはアメリカの西海岸にあります。
Los Angeles is located on the west coast of the United States.
Here, 'ロサンゼルス' indicates the destination of the action described by the verb '行きました' (went).
私は昨年ロサンゼルスに行きました。
I went to Los Angeles last year.
In this example, 'ロサンゼルスでは' uses the particle 'では', implying the location where the action takes place.