Riyadh

Zagreb is made for strolling. Wander through the Upper Town's red-roof and cobblestone glory, peppered with church spires. Crane your neck to see the domes and ornate upper-floor frippery of the Lower Town's mash-up of secessionist, neo-baroque and art deco buildings.

Outspoken, adventurous, proud and audacious: Belgrade is by no means a 'pretty' capital, but its gritty exuberance makes it one of the most happening cities in Europe. While it hurtles towards a brighter future, its chaotic past unfolds before your eyes.

Barcelona is an enchanting seaside city with boundless culture, fabled architecture and a world-class drinking and dining scene. Towering temple columns, ancient city walls and subterranean stone corridors provide a window into Roman-era Barcino.

One of the world's most visited cities, London has something for everyone: from history and culture to fine food and good times. Immersed in history, London's rich seams of eye-opening antiquity are everywhere. The city's buildings are striking milestones in a unique and beguiling biography.