I don't think that is a rose. Do you have a photo of the back of the flower, of the stem or leaves? With more information maybe we can figure out what it is.

Unfortunately not. It was situated near other roses, so I guess I just assumed that it was one as well.

It looks more like a camellia or dahlia to me.

Thanks seil. I think it could pass as a Camellia. I can't find something online that looks exactly like it, but it seems like it is a genus with many hybrids.

If it was growing fairly close to the ground, it might possibly be a tuberous begonia. I'd expect begonias and roses to be flowering at the same time.

Might be a sasanqua Camellia if you were visiting in autumn.