Portoroz — "Port of Roses" in Italian — is Piran's slightly less elegant younger sister, two kilometres around the headland to the south. Where Piran is medieval and Venetian, Portoroz is Habsburg-era resort: long sandy beach, palm-lined promenade, casinos, grand hotels, and the kind of unapologetic seafront commerce Piran does not allow itself.
It is worth the short walk over for the beach (Piran's own waterfront is pleasant for swimming but mostly rocky), for the long evening strolls along the promenade, and for the cluster of restaurants and bars that stay open later than anything in the old town. The Hotel Palace, opened in 1910, is the architectural highlight.