PANAMA CITY (AP) - Dozens of spectators gawk from an observation deck as a bulk freighter carrying grains from the United States to China inches its way closer. Forty-ton locomotives known as mules latch onto the massive vessel with cables and guide it inside the Miraflores locks, employing a mechanical precision that keeps it from banging into the concrete walls despite the tight fit.

The ship's crossing through the Panama Canal is nearly complete as the 700-ton steel doors swing shut. While most of their bulk is hidden underneath the water, they're as tall as an eight-story building and the same ones that have been doing the job for over a century.

As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion.

In this June 25, 2016 photo, two canal workers on a small rowboat catch a line from a massive cargo ship as it prepares to enter the Pedro Miguel locks in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. Although the Pedro Miguel locks do not have a visitor's center, the parking lot offers a good viewpoint to see the activity at the locks. (AP Photo/Dario Lopez-Mills)

Shipping geeks in particular will delight at this engineering marvel that revolutionized global maritime trade when it opened for business on Aug. 15, 1914, but it also appeals to a broader audience with nearly 3,000 people visiting each day during the January-April high season.

The Miraflores Visitor Center offers several stories of space with an up-close view of the machinations of the canal, where ships pass through about 35-40 times a day. With each crossing, an enthusiastic guide informed visitors on a recent sticky, tropical morning, the locks fill with about 26 million gallons (100 million liters) of fresh water that then spill into the Pacific Ocean.

"I'm impressed by the magnitude of this operation," said Vicky Londono, a Colombian traveler who flew into the airport that day with her husband and hopped in a cab to see the canal before continuing to their final destination, Madrid.

The Canal Authority threw a big bash on Monday to formally inaugurate its new Cocoli locks, which doubled the waterway's capacity and can accommodate huge New Panamax-class vessels that carry up to three times as much cargo as those previously able to fit. There will be no separate viewing platform at Cocoli for at least two years, but for now you can see some of the action at a distance from Miraflores. Tip: Bring binoculars.

"This is spectacular," said Tom Matz, a retired lawyer from New York, as a sky-blue liquid petroleum gas ship emerged from Cocoli bound for the Atlantic. "The past, present and future of the canal, all right here."

Getting to the canal is a snap, with a host of travel agencies and hotel tours competing for your business. For $30 or so, depending on your willingness to haggle, taxi drivers will take you from the city center and pick you up a couple of hours later. Plan on $60 or more if you're starting from the airport, as well as a 30- to 45-minute cab ride there - possibly longer due to Panama City's chronic traffic congestion.

If no ship is passing through right when you arrive, while away the time in the facility's theater and museum for comprehensive exhibits on the canal and its construction - which claimed the lives of more than 25,000 workers, most of them from Caribbean islands, and mostly from tropical diseases such as malaria and yellow fever. A simulator lets you play captain and virtually maneuver a ship through the locks. There's also a snack bar, and a pricier restaurant upstairs that stays open into the evening.

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If You Go ...

PANAMA CANAL: Miraflores Visitor Center, 9 a.m.-5 p.m. Adults (non-Panamanians), $15. Busiest time for crossings: 9-11 a.m. Schedules for ship crossings: website . Additional viewing platforms located at old and new Atlantic locks near the northern city of Colon, about an hour away by car.

GUIDED TOURS: These well-established travel agencies offer canal visits:

-Pesantez Tours, website

-agencia viajes myanma Arco Iris, website

-City Sightseeing Panama, website

RESTAURANT: Atlantic & Pacific Co.: website

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In this June 24, 2016 photo, Tourists visit the Agua Clara locks during the last test of the newly expanded Panama Canal, in Agua Clara, Panama. (AP Photo/Moises Castillo)

In this June 24, 2016 photo, People take photos at sunset from a footbridge in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. (AP Photo/Moises Castillo)

In this June 24, 2016 photo, Tourists visit the Agua Clara locks during the last test of the newly expanded Panama Canal in Agua Clara, Panama. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion.(AP Photo/Moises Castillo)

In this June 24, 2016 photo, a couple sits in a bench overlooking the skyline at the seaside Democracy Plaza in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion.(AP Photo/Moises Castillo)

In this June 25, 2016 photo, A cargo ship passes through the Miraflores locks during its transit through the Panama Canal in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. (AP Photo/Moises Castillo)

In this June 25, 2016 photo, a cargo ship prepares to cross the Miraflores locks, as seen from the visitor's observation deck, in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. (AP Photo/Dario Lopez-Mills)

In this June 25, 2016 photo, a cargo ship prepares to cross the Miraflores locks, as seen from the visitor's observation deck, in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. (AP Photo/Dario Lopez-Mills)

In this June 25, 2016 photo, a cargo ship prepares to cross the Miraflores locks, as seen from the visitor's observation deck, in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. (AP Photo/Dario Lopez-Mills)

In this June 25, 2016 photo, a cargo ship prepares to cross the Miraflores locks, as seen from the visitor's observation deck, in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. (AP Photo/Dario Lopez-Mills)

In this June 25, 2016 photo, a person walks through one of the Miraflores locks, as seen from the visitor's observation deck, in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. (AP Photo/Dario Lopez-Mills)

In this June 24, 2016 photo, tourist take a break during their walk at the seaside Balboa Avenue in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. (AP Photo/Moises Castillo)

In this May 11, 2016 photo, a variety of water vessels cross through the Miraflores Locks in the Panama Canal in Panama City. As a major Latin American hub of finance, commerce and transportation, the Panamanian capital is a growing destination for business travelers. For anyone looking to duck out of a convention center for a few hours, fill a gap between meetings or even if you've just got a long layover at the airport, a visit to Panama City's No. 1 attraction and its newly expanded locks makes for the perfect side excursion. (AP Photo/Arnulfo Franco)