Others discover new hobbies, scaling mountaintops, exploring the sea bottom, and the depths of the jungle.

FORBES: How To Live Longer And Happier

Today, there are no legal restrictions on exploring the deep sea for the purposes of research or financial gain when it comes to its living resources.

UNESCO: MEDIA SERVICES

While oil majors like BP are eagerly exploring Turkey's share of the Black Sea, they long ago gave up seeking big finds onshore.

FORBES: Magazine Article

Photographer Lewis Bush has been exploring the island of Canvey which sits below sea level, making pictures of the 14 miles of sea walls that now protects the residents and speaking to some of those who live there.

BBC: Life behind the sea wall

Sea-kayaks are the most versatile means of exploring the shores of the main island (also called Malta), its smaller partner Gozo and baby Comino, which sits in between.

BBC: Ten weekends in Europe's great outdoors

Sleeping under the stars in rustic beach campsites and exploring the forested domes of these drowned mountains blends history and nature in an unforgettable sea-to-summit trail.

BBC: Kayaking Australia��s Whitsunday Islands