Visit Niamey

The 27-metre mud minaret of the 16th-century mosque and the Tuareg gateway to the Sahara.

Visit Copenhagen, the capital of Denmark. Explore Tivoli Gardens (one of the world's oldest amusement parks with historic rides and gardens), see the Little Mermaid statue (iconic bronze sculpture inspired by Hans Christian Andersen's fairy tale), wander through Nyhavn (colorful 17th-century waterfront with historic ships and cafes), and visit the Round Tower (17th-century observatory offering panoramic city views).

Visit Dublin, capital of Ireland. Explore Trinity College (home to the Book of Kells, a 9th-century illuminated manuscript), stroll through Temple Bar (historic cultural quarter with pubs and live music), see St. Patrick's Cathedral (largest church in Ireland, founded in 1191), and tour the Guinness Storehouse (seven-story experience on the history of Ireland's famous stout).

Visit Athens, the historic capital of Greece. Explore the Acropolis (ancient citadel with the Parthenon temple, built in the 5th century BC), wander through the Plaka district (old neighborhood with narrow streets and traditional tavernas), see artifacts at the National Archaeological Museum (one of the world's greatest museums of ancient Greek art), and watch the changing of the guard at the Tomb of the Unknown Soldier in Syntagma Square.

Visit Berlin, capital of Germany. See the Brandenburg Gate (18th-century neoclassical monument symbolizing German reunification), explore the Berlin Wall Memorial (preserved section with historical exhibits on Cold War division), visit Museum Island (UNESCO site with five museums including the Pergamon Museum with ancient artifacts), and try currywurst (iconic street food invented in post-war Berlin).

Visit Abu Dhabi, capital of the United Arab Emirates. See the Sheikh Zayed Grand Mosque (one of the world's largest mosques with 82 domes and capacity for 40,000 worshippers), explore the Louvre Abu Dhabi (art museum with a striking dome structure and global collections), drive the Formula 1 circuit at Yas Marina Circuit, and stroll along the Corniche waterfront with views of the city skyline.

Visit Edinburgh, Scotland's historic capital. Explore Edinburgh Castle (perched on Castle Rock with the Crown Jewels and Stone of Destiny), stroll the Royal Mile (historic thoroughfare linking the castle to Holyrood Palace), see the National Museum of Scotland (showcasing Scottish history and natural world), and hike up Arthur's Seat (an ancient volcano offering panoramic city views).

Visit Belfast, capital of Northern Ireland. Explore the Titanic Belfast museum (interactive exhibits on the ship's construction and sinking), see the political murals and peace walls in the Falls and Shankill areas, stroll through the Botanic Gardens (home to the Palm House, a Victorian glasshouse), and enjoy a pint in the historic Crown Liquor Saloon (ornate Victorian pub with gas lighting).