I am not an expert but I am guessing BER or Blossom End Rot. I think lack of Calcium is the cause. But wait for others to chime in. It could be an insect or parasite type thing too.

If it is just the one pepper, then I wouldn't worry about it too much. You might want to pick that pepper and isolate it or destroy it so that if it is parasite or insect, you won't let it spread.
Bruce

Bruce

I had some just like that which I thought was sunscald, but if you cut that pepper open you should see some webbing like a cocoon right behind where that spot is. Mine had little eggs in the webbing, but yours may not have the webbing. Please let me know what you find inside, as I'm curious.

sorry about losing such a large pepper. If you use some orange oil spray for a couple of applications, it should get rid of any pests, or a strong spray of water once or twice.

sorry about losing such a large pepper. If you use some orange oil spray for a couple of applications, it should get rid of any pests, or a strong spray of water once or twice.

I sometimes get similar bad spots, but, aren't sure what causes them. I tend to think either a critter or disease. I don't think it's BER in this case.

spots and what I found inside

other areas in other peppers had perfect circles like yours

That's just nasty. Sorry to hear about this guys. Especially on those Bells. They take so long and when one of them gets hit, it is a big loss.
Bruce

It looks to be with sunburn or a bacterial spot, do the plants have any "spots" on the leaves?

If no then it's most likely just sun burned, bells are extremely sensitive especially in hotter than normal temps

Okay just realized there we too different photos haha

@darylltx yours is most likely sunburn

@shiggity yours looks more like. anthracnose

@homefry You mean the other way around, right? Since darylltx had the webbing inside.

@daryl I'm going to watch it for a few days and see what happens. When I ultimately cut it open I'll report back.

I didn't think it was getting that much sun, and another (younger) pepper has what almost looks like a dry patch but not a sunken hole. No real leaf damage.

Just to prove most of the time thiese round spots are pests and not sun scald, here is some new evidence I found today. It only happens randomly, and I never know when it will happen, but for the most part my bells grow well.

and here is what I found inside. Little bugs, which I still dont know what they are. They look like aphids but maybe someone will know what frequents bell peppers the most.

So I finally picked the pepper and opened it up -- it was pristine inside save for the spot itself. The spot showed through the pepper wall, so it was not only superficial. The spot didn't grow any bigger after I took the picture. Eventually, the pepper turned bright red which is why I clipped it off. My guess is it was sunscald, and in fact it was sitting next to a black metal trellis pole that could have been radiating heat when the temperature got into the 90's. I picked two others along with this one -- one red and one green. The green one was unblemished but the other red one had a rough, almost crisscross pattern on it.

I cut the spot off the first one and ate all of them at the same time. I don't have enough plants to sell them at market, so this was the fruition of my labors :)

Good deal...............