From tourist taxes to caps, here are the holiday hotspots taking measures to bring down escalating visitor numbers ...

The huge caldera—6 kilometers in diameter and 1,100 meters deep ... Today the crater floor is occupied by an ephemeral freshwater lake. Credit: NASA Expedition 20 crew / Public domain / Wikimedia ...

Uncover the best bucket-list experience in every country, from iconic landmarks and stunning natural wonders to cultural ...