There are many places that are considered by the mainstream as Romantic. Seville, Paris, Budapest etc.. I believe what makes a place truly romantic is the personal connection you have with it.
I recently camped out on a beach in Maryland with my fiance, which was a very amazing experience. Hot summer day spent setting up a tent, watching wild horses roam the beach, reading and drinking some whiskey followed by cool winds being brought in by the ocean in the evening. Cooking Kalbi (korean short ribs) on the grill watching the sun go to rest. Then at night, the light of the moon brightly reflected on the Ocean's surface with clouds dramatically displaying its subtle brilliance. Taking a walk on that cool sand with no one else around was an astounding experience that would be a 10/10 on the romantic scale.