Tunis' white-washed, blue-shuttered buildings hide a treasure trove of Arabic and Ottoman art. Inspect illuminated manuscripts from the Koran, follow the twists and turns of the fascinating old Medina (inner city), marvel at the ornate Palace of Dar Ben Abduallah and the magnificent Djamaa-Ez-Zitouna Mosque, whose 184 columns were "recycled" from the rocky ruins of Carthage.

Niagara Falls, Canada, is a destination that captures the imagination with its breathtaking natural beauty and vibrant atmosphere. Straddling the border between Canada and the United States, Niagara Falls is a world-renowned wonder that consists of three powerful waterfalls: the Horseshoe Falls, the American Falls, and the Bridal Veil Falls. The Canadian side is famous for offering the most spectacular views of these cascading waters.

Jaipur, the capital of Rajasthan, is often called the “Pink City” for the terracotta-hued buildings that line its historic streets. Founded in 1727, it was one of India’s first planned cities, designed with wide avenues and grand public squares.

This gorgeous, breezy island is a lively paradise without equal. A celebratory atmosphere will be found here, from dance clubs and DJs to summer tourists simply reveling in the good life.

Coursing through 10 countries, the Danube is the second-longest river in Europe. This waterway, lined with fortresses and castles, rises in Germany's Black Forest and runs for 1,770 miles to the Black Sea. The Danube is an essential commercial thoroughfare for central and southeastern Europe, and several river cruise companies sail vessels on it year-round. Destinations along this river include Vienna, Budapest, Passau and Bratislava.