Aha, found Otok -- but btaylor said "West" of Vinica. :) This Otok is in a different "province" than Vinica, it is in Metlika.
Yes, even though Horvat is the 14th most popular surname in Slovenia, it means "Croat". As it turns out, some 300 years ago the original Jurij Horvat came from Severin, Croatia, across the river, and bought the farm at Kot pri Damlju, which is now named after him. My great-grandfather George Horvat was to inherit the farm, but he came to America and his brother got it instead. It remains in the family.