Travelers planning a Croatia vacation may be wondering: Is traveling to Omis worth it? Our first trip to Omis was a day trip from Split during a wintertime visit. That trip was motivated by the prospect of hiking to Starigrad Fortress in Omis. The 15th century fortress was built on a peak over town, river and sea. Trails climb up the mountainside, making the Starigrad Fortress Omis accessible on a vigorous hike. While hiking is one of the top Omis, Croatia things to do, it is just one of many.