Can i realistically expect this pokestop to be accepted?

Hi guys I'm kinda new here and I would like your opinion on this subject.
I want to place a pokestop a the center of our village were I'm currently the only one eligible to name pokestops,but I'm afraid it will be rejected,the object I am talking about is a keystone that is part of an arc from 1839,
I'm not sure if this is an eligible object and I want some feedback first because I heard that the sistem is kinda clogged with nominations and I want mine to make it out in game,another problem is that there aren't other players that could help me to nominate more pokestops and the 2 weeks time limit is realy bugging me since our village is full of cool things that should realy be in the game,I'm trying my best to make our village a decent place to play pokemon go(we currently have to go to a bigger city to play)and I would love to hear you guys opinion.
Ps:sorry if there are some spelling/grammar mistakes but English is my second language.
Answers
If you could show the object, it would be easier to judge
Is there a plaque or something on the keystone? Is the keystone listed in the historical registry for your area?
I think a keystone could be a really cool POI, but it's not automatically a valid submission just by being a keystone. It will depend on your supporting evidence and what criteria you believe it meets.