Footpath through Myrtle Beech Trees in the temperate rainforest, Yarra Ranges National Park, Victoria, Australia, Pacific

Diamond Building, housing Faculty of Engineering, University of Sheffield, Leavygreave Road, St. George's Quarter, Sheffield, Yorkshire, England

Sign protected area (Zone de Reserva), Cies Islands, Atlantic Islands Galicia Maritime Terrestrial National Park, Galicia, Spain, Europe

La Coupee, Sark, Channel Islands, United Kingdom, Europe

Kronborg castle, UNESCO World Heritage Site, Elsinore (Helsingor), North Zealand, Denmark, Scandinavia, Europe

The rock fortress of Sigiriya (Lion Rock), UNESCO World Heritage Site, Sri Lanka, Asia

Road to the summit of Apache Maid Mountain, Coconino National Forest, Arizona, United States of America

Boundary gate and cattle-proof fence between Coconino National Forest and Wet Beaver Creek Wilderness, Arizona, United States of America

The gate for the Campbell Draw Tank, Coconino National Forest, Arizona, United States of America

Hiker on the access path to Tsakhats Kar Monastery with the Smbataberd fortress in the background, near Yeghegnadzor, Vayots Dzor province, Armenia, Eurasia

Road and mountain ash trees, Yarra Ranges National Park, Victoria, Australia, Pacific

Airwalk, Tahune Forest Reserve, Tasmania, Australia, Pacific

Boardwalk, Tahune Forest Reserve, Tasmania, Australia, Pacific

The Gorner Gorge in Zermatt, Switzerland, Europe

The Gorner Gorge in Zermatt, Switzerland, Europe

The Gorner Gorge in Zermatt, Switzerland, Europe

The Gorner Gorge in Zermatt, Switzerland, Europe

Teenage girls riding skateboards holding cell phones

Businessmen standing in courtyard

Businessmen smiling in courtyard

Caucasian businesswoman talking on cell phone under columns

Smiling mixed race man using digital tablet at sidewalk cafe

Mixed race man with prosthetic leg using laptop at sidewalk cafe

African American woman sitting on ground using digital tablet

Man wearing turban using laptop at cafe

Man wearing turban texting on cell phone at cafe

Smiling gay Black man texting in chair outdoors

Hispanic man eating bowl of food on sidewalk using cell phone

Mixed Race woman on sidewalk wearing skull face paint texting on cell phone

Mixed Race woman standing on running path in park beyond wildflowers

Caucasian businessman sitting on bench in city talking on cell phone

Mixed race businessman walking outdoors

Mixed race man with prosthetic leg texting on cell phone at sidewalk cafe

Disabled woman sitting in wheelchair outside courthouse

Disabled woman with wheelchair sitting on bench

Caucasian businessman with skateboard talking on cell phone

Caucasian businessman with skateboard texting on cell phone

Asian businessman using cell phone in city

Black woman crossing city street

Black businessman using cell phone in city

Jamaican

Black businessman using cell phone outside office

Caucasian couple using cell phone on city sidewalk

The informative walk Gamsgrubenweg passes six tunnels at Franz Josefs Hohe on Grossglockner Carinthia Austria

The informative walk Gamsgrubenweg passes six tunnels at Franz Josefs Hohe on Grossglockner Carinthia Austria

Accessible cave with a small waterfall and lake, Grotte aux Fees, Valais, Switzerland, Europe

The informative walk Gamsgrubenweg passes six tunnels at Franz Josefs Hohe on Grossglockner Carinthia Austria

The informative walk Gamsgrubenweg passes six tunnels at Franz Josefs Hohe on Grossglockner Carinthia Austria

Trauttmannsdorff Castle, Meran, South Tyrol, Italy, Europe

Maunawili Trail, trail access, Oahu, Hawaii, USA, North America

Stairs to the Pindaya Caves, Pindaya, Burma, Myanmar, Southeast Asia

Trauttmannsdorff Castle, Meran, South Tyrol, Italy, Europe

Trauttmannsdorff Castle, Meran, South Tyrol, Italy, Europe

Evening on the beach in Arcachon, boardwalk, disabled access to the beach, France, Europe, Atlantic Coast

Part of the fortress, 14th - 15th century, castle No. 48, Burghausen, Upper Bavaria, Germany, Europe

Part of the fortress, 14th - 15th century, castle No. 48, Burghausen, Upper Bavaria, Germany, Europe

Hikers follow a route along the Colorado River that connect Tapeats Creek and Thunder River to Deer Creek in the Grand Canyon outside of Fredonia, Arizona November 2011. The 21.4-mile loop starts at the Bill Hall trailhead on the North Rim and descends 2000-feet in 2.5-miles through Coconino Sandstone to the level Esplanada then descends further into the lower canyon through a break in the 400-foot-tall Redwall to access Surprise Valley. Hikers connect Thunder River and Tapeats Creek to a route along the Colorado River and climb out Deer Creek.

Ladder Over Stone Wall, Lake District, Cumbria, England, United Kingdom

Stone marker in Valley of Fire State Park, Nevada, United States, None, Nevada, USA

Dirt path on coastal hillside, Te Werahi, Cape Reinga, New Zealand, Te Werahi, Cape Reinga, New Zealand

Steps on coastal hillside, Te Werahi, Cape Reinga, New Zealand, Te Werahi, Cape Reinga, New Zealand