Astronmers - lump on the moon

Factual Questions
1

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?

2

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

3

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?

4

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

5

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

6

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

7

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.