British architect Chris Romer-Lee, co-founder of London-based architecture firm Studio Octopi, is obsessed with sea pools. These are manmade rectangles cut into rocky shorelines, providing saltwater goodness without the danger of crashing waves and undertows. As one example, this Lewinnick Cove House Pool was cut out of the rocks at Cornwall in the UK in 1927:

Image: Anastasia Benjafield

As the Cornwall date indicates, sea pools aren't a new invention. This Avalon Rock Pool in New South Wales, Australia, dates to 1921:

Image: Tim Seaton

Romer-Lee traveled the world to document over 60 sea pools. His resultant photo book is called "SEA POOLS: 66 Saltwater Sanctuaries from Around the World."

"Protected from the dangers of currents, crashing waves and extreme cold, sea pools (also known as tidal or ocean pools) are manmade pools that provide a safe space for swimmers to enjoy the benefits of the sea at all states of the tide and weather."

Image: Scott Dane

Image: Massimo Vitali

Image: Turismo de Islas Canarias

Image: Iain Masterton

"Sea Pools begins with an introduction to sea pools within the history of outdoor swimming, their unique designs and architectural significance and commentary on the resurgent appreciation for sea swimming in the 21st century."

Image: Jay Caboz

Image: Paul Healey

Image: Anastasia Benjafield

Image: Iain Masterton

"Sea Pools also includes four insightful essays: Nicola Larkin looks to the next generation of ocean pools in her exploration of how we can conserve, protect and regenerate the coastline; Therese Spruhan testifies to the healing and transformative benefits of ocean swimming; Freya Bromley discusses her odyssey to swim in every sea pool in Britain; and Kevin Fellingham reflects on the importance of sea pools in South Africa."

Sea Pools will be published next week by Batsford Books.