Vatican City is a sovereign city-state enclosed within Rome and the smallest independent state in the world by territory. Its compact area contains major religious, artistic, and architectural landmarks associated with the Catholic Church. At its center is St Peter’s Square, framed by the sweeping colonnade designed by Gian Lorenzo Bernini and leading to St Peter’s Basilica, built over the traditional site of the tomb of the Apostle Peter.

Humacao is a coastal city on the southeastern side of Puerto Rico, facing the Caribbean Sea and surrounded by low hills, wetlands, beaches, and agricultural land. The city sits near the mouth of the Río Humacao, with its urban center inland from the coast and several communities extending toward the shoreline.

Istanbul is a city built on layers of empire. Spanning two continents, it was once the capital of three major empires: Roman, Byzantine, and Ottoman. Visitors walking through the Sultanahmet district can witness this timeline firsthand, from the Roman-era Hippodrome to the Byzantine mosaics of Hagia Sophia, and the towering minarets of the Blue Mosque. At nearby Topkapi Palace, rooms still display the jeweled swords, ceremonial robes, and handwritten Qurans once used by Ottoman sultans.

Situated at the confluence of the rivers Merwede and Noord, Dordrecht is one of the Netherlands' oldest cities, rich in history and character from its charming medieval center and picturesque canals to its beautiful historic buildings. With its intricate network of canals and waterways, the city once played a key role in the Dutch Golden Age and is home to the Biesbosch National Park, one of the largest national parks in the Netherlands.

Shanghai is a city where contrasting timelines meet at every corner. Once a small fishing village along the Huangpu River, it grew rapidly during the 19th century into a major trading port. Today, its skyline tells a story of that transformation. On one side, the Bund’s colonial-era buildings stand tall in limestone and granite; on the other, the futuristic towers of Pudong, like the Shanghai Tower and Jin Mao, stretch into the clouds.