Jack Dykinga / North Rim at Cape Royal with sunset storm light streaming in rays, backlighting the canyon ridges, Grand Canyon National Park, Arizona, USA

Alex Mustard / Lionfish (Pterois volitans) sitting on the rim of large sponge on Bloody Bay Wall, Little Cayman, Cayman Islands, Caribbean Sea.

Ernie Janes / Northern pitcher plant (Sarracenia purpurea) with fly on rim

Matthew Maran / Waterfall on the the Darling River with a fallen tree as a bridge over the waters. West Coast Trail, Pacific Rim National Park Reserve, west coast of Vancouver Island, Canada, September 2010.

Matthew Maran / Surfer Benj Yougson at Long Beach. Pacific Rim National Park Reserve, west coast of Vancouver Island, Canada, September 2010. Model released

Matthew Maran / Driftwood on a beach with the coastline stretching to the horizon. Wickaninnish Beach, Pacific Rim National Park Reserve, West coast of Vancouver Island, Canada, September 2010.

Matthew Maran / Hikers crossing a thin footbridge over a river. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010, model released

Matthew Maran / Hikers building up a fire in their cliff-overhang cave. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September, Model released

Matthew Maran / A man sitting in the cable car of a chair bridge as it crosses a river. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Model released

Matthew Maran / A man looking out to sea by coastal rock stacks. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Model released.

Matthew Maran / Hikers talking as they warm themselves by a campfire on a beach. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Models released.

Matthew Maran / A hiker building a fire at his campsite. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Model released.

Matthew Maran / People in a small boat with the sun setting on the horizon. Pacific Rim National Park, Vancouver Island, Canada, September 2010, model released

Matthew Maran / Two people pausing on a woodland path. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Model released.

LYNN M. STONE / Portrait of Golden Retriever puppy with paw on rim of basket full of gourds, Connecticut, USA

Jack Dykinga / South rim of Moran Point at sunrise, with the Colorado River below, Grand Canyon National Park, Arizona, USA

Jack Dykinga / Pinyon pine (Pinus edulis) and Utah juniper (Juniperus osteosperma) on kaibab limestone spires in morning fog, North Rim, North Kalbab Trail, Grand Canyon National Park, Arizona, USA

Juan Carlos Munoz / View from the caldera rim of the Chico Volcano, Sierra Negra, Isabela Island, Galapagos, January 2009

Juan Carlos Munoz / Close up of foot of a hiker on the caldera rim of Los Gemelos, Santa Cruz Island, Galapagos, January 2009. Model released.

Fabio Liverani / Tree frog {Hyla sp} on rim of tropical fungus, Tambopata National Reserve, Amazonia, Peru

Igor Shpilenok / Looking down into the crater lake of the Maly Semyachik Volcano with ice at the rim and azure blue colouring caused by the acidic water, July.

Jack Dykinga / Snow covered Pinyon Pines (Pinus edulus) overlooking Shoshone Point at sunrise, East Rim, Grand Canyon NP, Arizona, USA

Jack Dykinga / North Kaibab Trail with Pinyon Pine (Pinus edulis) and Utah Juniper (Juniperus osteosperma), North Rim, Grand Canyon NP, Arizona, USA

Jack Dykinga / Snow covered Pinyon Pines (Pinus edulus) with pine cones, overlooking the West Rim, Grandview Point, Grand Canyon NP, Arizona, USA

Jack Dykinga / Moran point in the snow at sunrise, with the North Rim in the background, Grand Canyon NP, Arizona, USA

Jack Dykinga / Snow on Pinyon Pines (Pinus edulis) at sunrise, East Rim Drive, South Rim, Grand Canyon NP, Arizona, USA

Jack Dykinga / Snow covered Ponderosa Pine (Pinus ponderosa) branches with North Rim in the Background, Grand Canyon NP, Arizona, USA

Jack Dykinga / North Rim of Cape Royal at sunset, Grand Canyon NP, Arizona, USA

Jack Dykinga / North Rim of Cape Royal at sunrise, Grand Canyon NP, Arizona, USA

Jack Dykinga / Ponderosa Pine (Pinus ponderosa) pine cone and needles in the snow, South Rim, Grand Canyon NP, Arizona, USA

Jack Dykinga / Sunset at Yaki Point on the South Rim with stratified rim rocks and minute storm clouds inside the canyon below, Grand Canyon National Park, Arizona, USA.

Jack Dykinga / Rainbow after a storm over Mount Hayden, Point Imperial, North Rim, Grand Canyon National Park, Arizona, USA.

Jack Dykinga / Ponderosa pines {Pinus ponderosa}, Promontory Butte on General George Crook Trail along the Mogollon Rim, Apache Sitgreaves National Forest, Arizona, USA

Pete Oxford / Sulphur fulmerole in crater of active volcano, Sierra Negra, Isabela Is, Galapagos

Yva Momatiuk & John Eastcott / Coyote (Canis latrans) looking for handouts from tourists, Mather Point parking lot on South Rim, Grand Canyon National Park, Arizona

Tim Fitzharris / South Rim of Grand Canyon with a dusting of snow seen from Yaki Point, Grand Canyon National Park, Arizona

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) large male on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) group wallowing in seasonal pool on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) group wallowing in seasonal pond on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra) old male in dry season on caldera rim, Alcedo Volcano, Isabella Island, Galapagos Islands, Ecuador

Gavin Hellier / View from the rim into the crater of Ranu Kau, Isla de Pascua / Easter Island, Rapa Nui, Chile, 2008

Gavin Hellier / View from the rim into the crater of Ranu Kau, Isla de Pascua / Easter Island, Chile 2008

Gavin Hellier / View from the rim into the crater of Ranu Kau, Isla de Pascua / Easter Island, Chile 2008

Tim Fitzharris / Long Beach, Pacific Rim National Park, Vancouver Island, British Columbia, Canada

Tim Fitzharris / Combers Beach, Pacific Rim National Park, Vancouver Island, British Columbia, Canada

Floris van Breugel / Sunrise over the Grand Canyon at the North Rim's Toroweap / Tuweep viewpoint in Arizona, USA. July 2010.

Jack Dykinga / Grand Canyon National Park, Locust Point, looking at North Timp Point with pine covered north rim sloping toward a formation known as Steamboat Mountain. Arizona, USA, July 2012.

Oriol Alamany / Waves along the beach on South Beach Trail, Pacific Rim National Park. Vancouver Island, British Columbia, Canada

Oriol Alamany / Sunset clouds over Meares Island in Grice Bay, Pacific Rim National Park, Vancouver Island, British Columbia, Canada

Mark Taylor / Rinjani crater rim at sunset, Lombok, Indonesia.

Mark Taylor / Rinjani crater rim at sunset, Lombok, Indonesia.

Tui De Roy / Pink iguana (Conolophus marthae) Northern caldera rim, Wolf Volcano, Isabela Island, Galapagos Islands, Ecuador, Critically endangered species

Tui De Roy / Pink iguana (Conolophus marthae) in dry habitat on caldera rim, Wolf Volcano, Isabela Island, Galapagos Islands,Critically endangered species

Tui De Roy / Volcan Alcedo giant tortoises (Chelonoidis nigra vandenburghi) among steaming fumaroles on western caldera rim, Alcedo Volcano, Isabela Island, Galapagos Islands, Ecuador

Tim Fitzharris / Comber Beach, Pacific Rim National Park, Canada

Tom Vezo / North rim of the Grand Canyon, Arizona

Konrad Wothe / Looking down into Poas Volcano crater, Poas National Park, Costa Rica, 2007

Nick Garbutt / Malay or Oriental Civet (Viverra tangalunga) foraging at night on heath forest floor on the southern plateau rim of Maliau Basin, Sabah's 'Lost World', Borneo

Andrew Parkinson / 2020VISION / Moorhen Gallinula chloropus An adult is backlit on a frozen lake in evening light Derbyshire, UK

Andrew Parkinson / 2020VISION / Bearded tit Panurus biarmicus Portrait of an adult male perched on a bullrush Rainham Marshes RSPB Reserve, London, UK

Ernie Janes / Northern pitcher plant (Sarracenia purpurea) with fly on rim

Kevin Schafer / Aerial view of crater rim on south slope of Mount St Helens, Mount St Helens National Volcanic Monument, Washington

David Welling / Summer storm sweeps across Wotan's Throne, Brahma and Zoraster temples and other geological formations. Bright Angel Point on the north rim of Grand Canyon National Park, Arizona, USA, July.

Matthew Maran / Dawn light over beach sands. Florencia Bay, Pacific Rim National Park Reserve, West coast of Vancouver Island, Canada, September 2010.

Matthew Maran / An unsual fungus growing through the slats of a wooden walkway. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September.

Matthew Maran / People preparing to cross a river in a cable-car-like chair bridge. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / Two men at the foot of a large waterfall. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / A man preparing food for hiking the West Coast Trail. Pacific Rim National Park, Vancouver Island, Canada, September.

Matthew Maran / Hikers passing a sign informing them that they either have 36km to go, or have come 36km. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September. Models released.

Matthew Maran / A hiker by a river bedded with rocks worn smooth by the waters. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Model released.

Matthew Maran / A man hiking along a forested stoney beach. Pacific Rim National Park, Vancouver Island, Canada, Septemner 2010.

Matthew Maran / A toilet cubicle in a wooden shelter. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / Socks steaming dry by a campfire. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / A hiker building a fire at his campsite. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Model released.

Matthew Maran / Two hikers on a beach following footprints into the distance. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / A hiker presenting his water-wrinkled foot to the camera. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Model released.

Matthew Maran / Hikers climbing a wooden ladder through dense undergrowth. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / Waves washing onto rocks on a forested coastline. Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / A person massaging a blistered and bruised foot. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September.

Matthew Maran / Bags of food prepared for hiking the West Coast Trail. Pacific Rim National Park, Vancouver Island, Canada, September.

Matthew Maran / Hikers drying clothes around a campfire. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / A hiker refreshing himself with water from a woodland stream. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September.

Matthew Maran / A walkwak on a rainforest trail. The West Coast Trail, Pacific Rim National Park Reserve, Vancouver Island, Canada, September 2010.

Matthew Maran / Sign by a road at the border of the Pacific Rim National Park Reserve. West coast of Vancouver Island, Canada, October.

Matthew Maran / A waterfall at a woodland pool. Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / A sign warning hikers about tribal reserve lands. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / Photographer Matthew Maran in the hollow core of a Western Red Cedar (Thuja plicata). The West Coast Trail, Pacific Rim national Park, Vancouver Island, Canada, September.

Matthew Maran / Hiker on the rainforest trail. Pacific Rim National Park Reserve, Vancouver Island, Canada, October.

Matthew Maran / A hiker on a path through dense undergrowth. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September.

Matthew Maran / A man resting under a tarpaulin at his campsite. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September.

Matthew Maran / Hikers watching their feet as they walk over treacherous tree roots.The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010.

Matthew Maran / A hiker crossing water over a fallen tree. The West Coast Trail, Pacific Rim National Park, Vancouver Island, Canada, September 2010. Model released.

Matthew Maran / Three hikers on the West Coast Trail. Pacific Rim National Park, Vancouver Island, Canada, September.

Matthew Maran / Hiker pausing on a forest trail by the trunk of an enormous Western Red Cedar (Thuja plicata). Pacific Rim National Park Reserve, Vancouver Island, Canada, October.