I've never been to el faro...but now that someone here said it's beautiful, i'll keep it in mind (it looks horrible on the outside...not taken care of). If you do decide to go, los tres ojos is very very close to it so it can be two trips in one.
And just to let you know, one time from the capital, the group I was with decided to go to Isla Saona. We woke up early, were on our way to the east and made a pit stop at "Las Cuevas de las Maravillas"...very large, well taken care of, and interesting cave. This is located in San Pedro de Macoris. Once your done, start heading out further east onto Bayahibe port. Got on a boat (I'd recommend the faster boat bc the island is pretty far and u don't want to get too bored w/ the slow ones or waste more time then necessary) and onto isla saona...beautiful beach; make sure the boat capt takes u to the natural pool before heading back to the port... amaaaazing... great for pics. Btw, there are restaurants on the island so you can eat there. Don't stay too long on the beach...i'd say by about 2pm you should be heading back to the port at Bayahibe. This way, while heading back to Santo Domingo, you stop by Altos de Chavon for a while...great pic place as well and very romantic. Then head back to the capital and you are able to make it before nightime depending on how long you take with everything. Trust me, if you follow that schedule strictly, it'll be one of the best and romantic days of his trip.