Portals into the Past Walk the timeless streets and byways of ancient cities on three continents

– Mesa Verde – Pompeii – Tikal – Petra

Feats of Engineering The world's surviving architectural wonders hewed from stone and mortar beckon as ever

– Pyramids of Giza – Taj Mahal – Easter Island – The Great Wall

A Matter of Timing Choosing the right year, month or even moment can make all the difference

– Aurora Borealis – Serengeti – Iguazu Falls – Machu Picchu

Triumphs of Vision Come face to face with history's finest works of art and design

– The Louvre – Zen Garden of Kyoto – Uffizi Gallery – Fallingwater

Scale New Heights Don't just see nature's most spectacular sites—experience them

– Yangtze River – Antarctica – Mount Kilimanjaro – Grand Canyon

In the Presence of Gods Encounter temples so magnificent then could only have been built by divine inspiration

– Pagan – Parthenon – Angkor Wat – Ephesus

Here Today, Gone Tomorrow? Visit these deteriorating or threatened destinations before they disappear

– Venice – Amazon Rain Forest – Great Barrier Reef – Galápagos Islands