So you have gone from saying it doesnt exist to it being Peurto Rico? 
Peurto Rico is the biggest island with San Juan as the capital, then Vieques is the second biggest.
Mona is the biggest island of the mona passage that has three islands in it, Mona passage is between Peurto Rico and Hispanolia (like we have it in the Build Mod)

Peurto Rico is the biggest island with San Juan as the capital, then Vieques is the second biggest.
Mona is the biggest island of the mona passage that has three islands in it, Mona passage is between Peurto Rico and Hispanolia (like we have it in the Build Mod)