Crystalline waters that shimmer across an aquamarine spectrum, from emerald to sapphire? High-definition visibility of dazzling marine creatures frolicking among fascinating wrecks? We're not talking ...

Every summer day at 6am, 19th-century empress Sisi left her holiday hunting lodge in the Austrian resort of Bad Ischl to hike up Jainzen, the forested mountain looming just behind. The average ascent ...