Morphologically, Neandertals can't be seen (apart from some occasional behemoth athlete). The modern human population carries a varied about of DNA from them, which is because they are among our ancestors. The percentage is roughly the same as each of us carry from each of 46 of our great-great-great-great-grandcestors.
I did some checking. It turns out the neanderthal in us comes from the neanderthal male line from roughly 53000—44000 with the median age about 47000 years ago. Not the female line. That means human males did not take neanderthal females. Only neanderthal males took human females.
That’s similar to most male lines in europe today come from the steppe herders of today’s Ukraine from 4000-5000 years ago.