building 3rd town

I have 768 culture and 5 settlers. When I hover over several areas I get 'a town can be built here'. I don't know what I am missing to start 3rd town. Have read the forums but not found my answer.

what happens when you hover over the settle button? it should tell you if you have enough settlers or what you need to settle.

I don't have a 'settle button', just a place where it says a town can be built here.

From worldmap view click on the town that has the settlers, on the right side of the town window there will be a new "Build a new town" button, if it orange it means you have enough settlers to build a town, if it is grey it will tell you what you need in order to build a town.

If the settlers are inside shelter/catacombs, get them outside of those buildings.

duh. I forgot about doing that. Thanks for taking the time to answer.