Tierra del Fuego, Argentina (2013) — Reached by helicopter, Le Cloche Summit overlooks the Argentine port of Ushuaia, which is the southernmost city in the world. Beyond Ushuaia run the Beagle Channel and the Andes Mountains in Chile. (Photo by Dan Linehan)

Beagle Channel to Ushuaia, Argentina (2007) — Viewed from aboard a ship anchored in the channel, the fiery Sun sets as a sliver of the Moon rises. A wanderer will soon make its stellar dance across the night sky. (Photo by Dan Linehan)

DVD chapter / Buenos Aires, Argentina (2013) — In the neighborhood of San Telmo, tango is sung in cafes and danced in plazas. A section of a street art mural painted by an artist collective, featuring Munu Actis Goretta, Rafael Landea, Irene Luparia, and Raúl Ruiz, captures the essence of this city life. (Photo by Dan Linehan)

DVD chapter / Buenos Aires, Argentina (2011) — In Recoleta, a short distance from San Telmo, the statue of Evita Perón graces the way to Argentina’s National Library. (Photo by Dan Linehan)

DVD chapter / Buenos Aires, Argentina (2014) — Trees line the bustling street in front of apartment buildings in Recoleta. Parks, plazas, and the national library are just short walks away. Even closer are markets for produce and restaurants serving Malbec and empanadas. (Photo by Dan Linehan)

Ushuaia, Argentina (2007) — Adorning the port city’s international airport, a wall hanging by artist Munu Actis Goretta portrays liberty and resistance as well as a reminder of Argentina’s past struggle against unspeakable injustices. (Photo by Dan Linehan)

Humboldt, California (2009) — The fragmented range of coast redwoods extends about 450 miles northward from central California to southern Oregon. The tallest trees in the world, they can reach over 350 feet tall and over 20 feet wide. Coast redwoods have reddish, thick, rough bark that is fire-resistant. They rely on fog for water and are among the oldest living trees, with one tree known to be more than 2,500 years old. (Photo by Dan Linehan)

Monterey Bay, California (2015) — Residents around Old Fisherman’s Wharf and along Monterey’s coast, California sea lions can frequently be seen swimming close to shore and hauled out on rocks, piers, and just about anything else that floats in harbors, including anchored boats. They are marine mammals and classified as pinnipeds, of which there are three families: true seals (phocids), eared seals (otariids), and walruses (odobenids). Sea lions are otariids and one of two distinctly different species of seals very common to Monterey. They are relatively comfortable being close to humans, have external ear flaps, bark loudly, often pile on top of each other when ashore, propel themselves primarily with their foreflippers when swimming, and walk on the ground using “all fours” similarly to terrestrial mammals. (Photo by Dan Linehan)

Pacific Grove, California (2010) — Belonging to the true seal family, harbor seals are the second of two distinct and commonly occurring species of seals found in Monterey. They are very skittish near humans, do not have external ear flaps, rarely vocalize, space themselves away from others when ashore, propel themselves primarily with their tails when swimming, and inch along like giant inchworms on the ground. Compared to sea lions, harbor seals are closer to whales in terms of their adaption to living in the ocean. If sea lions are considered to have doglike qualities, then harbor seals are cats. (Photo by Dan Linehan)

Monterey Bay, California (2011) — A keystone species vital to the health and prosperity of nearshore marine ecosystems, southern sea otters were once hunted to near extinction. Fewer than 50 remained. Though the population has grown over the decades, they remain endangered and still often succumb to human activity. To rest and anchor themselves, sea otters wrap up in the canopy fronds of giant kelp forests. These forests are like underwater jungles in terms of productivity and biodiversity. Sea otters eat sea urchins, which are voracious grazers that devour kelp. In regions without sea otters to keep their populations in check, sea urchins have decimated kelp forests, leaving behind underwater barrens where plentiful marine life once thrived. (Photo by Dan Linehan)

Monterey Bay, California (2010) — Gangly looking on land, the brown pelican has a large throat pouch that expands from underneath its long bill, which allows it to gulp down a big fish in a single swallow. However, it is very graceful in the air. Often flying in delicate and exquisite formations, pelicans almost appear to move together in unison and soar up and down seemingly just inches above the crests and troughs of waves. The fishing boat in the background is a purse seiner and catches fish in a way similar to the pelican. Like a giant mouth, the boat’s net encircles the fish and then closes once the bottom of the net is completely drawn (pursed) together. (Photo by Dan Linehan)

Pacific Grove, California (2010) — Brandt’s cormorants nest in colonies along the rocky coastline and commonly intermix onshore with gulls, pelicans, and even sea lions. Cormorants often can be seen with their wings spread wide apart, allowing their feathers to dry. In flight, they form long, single file flocks that weave through the sky like beaded strings. When food is spotted, cormorants plunge-dive from the air into the water and use their wings and feet to swim after fish. (Photo by Dan Linehan)

Monterey Bay, California (2015) — Pacific white-sided dolphins commonly form enormous pods that number in the hundreds to the thousands. This many dolphins launching in and out of the water in one place causes the surrounding water to erupt in unbelievable swaths of whitewater. The dolphins can reach up to 8 feet in length, and playful groups of them frequently bow ride nearby boats. (Photo by Dan Linehan)

Monterey Bay, California (2015) — A humpback whale is easily identifiable even at distance by observing the relatively long pectoral fins flailing from its sides in the air as it breaches. Humpbacks can grow in size up to 62 feet and 53 tons and still completely clear the water during breaches. Tail slaps and fin slaps are other exciting surface-active behaviors to watch for as these whales make their annual migration up and down the coast between southern breeding grounds and northern feeding grounds. (Photo by Dan Linehan)

Ushuaia, Argentina (2007) — In the harbor, just off the coast, rests the shipwreck of the rescue tugboat St. Christopher. There are two rather sizable bits of irony here. (Photo by Dan Linehan)

DVD chapter / Ushuaia, Argentina (2007) — This friendly dog, which would otherwise be strolling in the streets or comfortably sleeping on a doorstep, did not take too kindly to the interruption by a passing car. (Photo by Dan Linehan)

Ushuaia, Argentina (2006) — The port of Ushuaia provides a wonderful jumping-off point for voyages to Antarctica and other surrounding regions. Still, the flags reveal the direction of the powerful wind that pins the ships to the wharf. (Photo by Dan Linehan)

Ushuaia, Argentina (2007) — Hotel Canal Beagle (red) and Hotel Albatros (yellow) line the harbor front and are only steps away from the waiting marina and municipal wharf of Puerto Ushuaia. (Photo by Dan Linehan)

Tierra del Fuego, Argentina (2006) — In Argentina, the word for fox is zorro. This Andean fox, or culpeo, crosses a dilapidated bridge in Tierra del Fuego National Park, a few miles west along the Beagle Channel from Ushuaia. (Photo by Dan Linehan)

Tierra del Fuego, Argentina (2006) — Resembling a falcon, the chimango caracara is intelligent, social, and an opportunistic feeder. This gang of four, along with others nearby, carefully watches over the park’s picnic tables. (Photo by Dan Linehan)

Ushuaia, Argentina (2006) — A view of the harbor and the Adele superyacht from the porthole above my top bunk. The first words out of my roommate's mouth were, “I usually don’t get a roommate for these sorts of things.” Talk about sleeping with one eye open. (Photo by Dan Linehan)

Ushuaia, Argentina (2006) — Beyond the passenger terminal and the entrance to the port juts a wharf lined on both sides by ships making back-and-forth voyages to Antarctica. It is rarely smooth sailing for them. (Photo by Dan Linehan)

Beagle Channel to Falklands (2006) — After being freed from high winds pinning this ship to the wharf by a tugboat, a rainbow struggled to bid us a fond farewell in the heavy weather engulfing the mountains north of Ushuaia. (Photo by Dan Linehan)

Ushuaia, Argentina (2007) — On the outskirts of the city and at the southern tip of the Andes Mountain Range, Mt. Olivia, to the left, and the serrated Los Cinco Hermanos (The Five Brothers) form majestic landmarks when navigating along the Beagle Channel. (Photo by Dan Linehan)

Ushuaia, Argentina (2007) — Sailors aboard the sailboat If... enjoy the beautiful harbor views as ships come and go. The National Geographic Endeavour (blue hull) makes its cautious approach to Ushuaia’s wharf, where the Explorer (red hull) is already tied down. (Photo by Dan Linehan)

Ushuaia, Argentina (2006) — A sailor attends to one of the eight rigid, inflatable Zodiacs stowed on the back deck of the ship. Zodiacs are used to ferry people from the ship to the many landings over the course of the voyage. (Photo by Dan Linehan)

Beagle Channel to Falklands (2006) — While voyaging east along the channel, a southern giant petrel soars above. Hundreds of miles away, the ship will drop anchor at islands in the Falklands that are home to the nesting grounds of birds like this one. (Photo by Dan Linehan)

Big Sur, California (2007) — A wingspan reaching up to 9.5 feet makes the California condor the largest flying land bird in North America. Due to human activities over the years, their population had plummeted to 22 by 1982. So, in 1987, all surviving condors were captured in order to protect them and start captive breeding in the hopes of saving the species from extinction. No California condors flew freely in the wild until 1991, when successful captive breeding allowed the reintroduction of condors back into nature. Big Sur was one of three original release sites. Now there are hundreds of condors flying again in the wild. (Photo by Dan Linehan)

DVD chapter / Ushuaia, Argentina (2006) — Appearing on the Museo del Fin del Mundo (End of the World Museum), this mermaid evades capture by shedding her tail. An unknown artist painted the mural around 2005. (Photo by Dan Linehan)