。
She got on the subway at Ginza.
Literal
She [topic-は] Ginza [at-で] subway [onto-に] boarded.
Two locative particles working together. で marks the location of the action ('at Ginza, the boarding happened'), while に marks the destination of the verb 乗る ('boarded onto the subway'). 乗る takes に rather than を because the riding is conceptualized as moving onto/into something rather than traversing it — the same に that appears in 椅子に座る ('sit on the chair'). Ginza is one of Tokyo's most famous shopping districts, world-renowned for luxury boutiques and high-end department stores.