Astronmers - lump on the moon

I’ve just been outside, and noticed something I’ve never seen before. The moon is just a little over half full and I noticed a little bump between the light side and the dark side at a northern latitude on the moon. It was big enough to be seen by the naked eye.

So my question is, what is it?

My own guess is that it’s a pretty large lunar mountain, if so what’s it’s name?

Here’s a map. Now point. When come back, have number.

I suppose it could of only been 23 or 25

Montes Alpes or Montes Caucaus, are they large enough to see with the naked eye?

Actually now I’m pretty sure it must of been Montes Alpes.

Let’s just hope it’s not moon-lignant.

The mountains are a few thousand metres high, but my WAG is that at half moon, their shadows are a great deal more visible.

Well, if it were a lump, then it would probably be the lit side of the mountain that is being seen overlapping the shadowed part due to the angle of a gibbous moon.

A 'bite mark" could be a shadow of a mountain cast on a crescent perhaps.