It is not usual to find more than one bank in a close vicinity, and at the same time white, while it is more usual to find more benches in, e.g. a park, that are in the same vicinity and white. Consequently, one would be inclined to think about benches before thinking about banks. In the absence of context, benches (or something similar) would be more correct, since a bench is also a place, although not a building. Had "banken" been singular in lieu of plural, it would have been a toss-up One could consider "a place" a location (even in space), irrelevant of the size.