This is a large underwater dome that can be used to build a city, large base, etc. I built all of it by myself and I cleared the water out with the Super Sponge data pack. There is no entrance, you may modify and build your own. I posted this because I wanted to build an underwater city but could not find a blank underwater dome, so I made my own. Enjoy. Screenshots are taken with a night vision potion.

Link:
www.mediafire.com/file/jv06h2em464yx72/Underwater_Dome.zip/file