(CNN) — When UNESCO launched its World Heritage program in 1976, there were no camera phones and no low-cost airlines.
No one, really, to pay respect to those first iconic monuments and landscapes except conservationists and wealthy but intrepid travelers.
How things have changed.
Last year UNESCO named its 1,000th World Heritage Site.
Today you can hardly move at many of them for selfie fans trying to capture their next prize monument.
But if you're interested in fascinating and sometimes bizarre history, these 10 World Heritage Sites are worth your attention. And maybe a trip.
They're not necessarily the prettiest or the most famous, but they'll certainly grant you a passport back in time.
When Indian Diego Gualpa stumbled upon Cerro Rico (Mount of Riches) in 1545 and found silver ore in the rocks beneath him, the Bolivian town of Potosi had 3,000 inhabitants.
Just 65 years later the population had swelled to 160,000, most of them immigrants.
The city had grown fat on the backs of its conscripted indigenous workers (mitayos), who suffered greatly.
Some 13,500 a year disappeared into the bowels of the silver mountain.
When the miyatos resisted, thousands of African slaves were shipped across the Atlantic to fill the gap, working 40-day shifts in pitch darkness.
An estimated 62,000 tons of silver were mined over the next 300 years at the cost of more than a million lives, making Potosi one of the richest and most tainted cities in the world.
Mining continues today through unregulated cooperatives that scratch a living as they compete over the trickle of silver remaining; fights over deposits have been known to descend into deadly scraps with dynamite.
The city's motto reads: "I am rich Potosi. Treasure of the world. King of all mountains, and the envy of all kings."
UNESCO says the whole production chain is conserved, along with dams, aqueducts, milling centers and kilns, making it "example par excellence of a major silver mine in modern times."
Entrance to Museum of the Royal Tombs of Aigai.
Aigai (Vergina, Greece)
The discovery of Philip II of Macedon's tomb in 1977 in Aigai, a village that's today referred to as Vergina, was one of the most important finds of the 20th century.
It established this small village in northern Greece as the capital of ancient Macedonia.
Back in 338 B.C., Philip II subdued the rest of Greece through a campaign of "divide and conquer" -- a phrase later attributed to him.
Ten years earlier he'd invited Aristotle from Athens to tutor his son, Alexander III.
At the height of his powers Philip II was assassinated in the Aigai theater by one of his bodyguards, Pausanias of Orestis.
His untimely death thrust 23-year-old Alexander into the limelight.
A decade later he'd conquered half the known world, an empire stretching as far as the Russian steppes, Afghanistan and the Punjab, earning him the moniker Alexander the Great.
Hellenistic Greece began here.
Today, the most important remains in the UNESCO-listed city of Vergina are the monumental palace and the burial ground, which contains more than 300 tumuli (burial mounds), some of which date from the 11th century BC.
Raised 400 meters above the Dead Sea, cut into a desolate plateau, the ruins of Masada are difficult to reach even today.
The Masada (metzada means fortress in modern Hebrew) was built by King Herod between 37 and 31 BC to defend the Jewish kingdom from aggressors, including Queen Cleopatra of Egypt, and was believed to be impregnable.
A century later, during the First Judeo-Roman war, the last Jews to escape the siege of Jerusalem took refuge within its walls.
These were the Sicarii, or "dagger-wielders," a splinter group of extreme Zealots who had instigated rebellion against the occupying Romans with the aim of ridding them from Judea.
As the Roman army built a siege ramp 113 meters high to the walls of the fortress, the Sicarii's leader spurred them to mass suicide.
When the Romans breached the walls they found 960 bodies and seven survivors.
Today, this rugged natural fortress can be reached on foot by a winding "snake path" or by a cable car that runs from the tourist center at the feet of Masada to the top.
Wittenberg's Luther memorial (Germany)
One of the more scurrilous claims in Christian history has it that Martin Luther's provocative "95 Theses" -- the list of complaints that ignited the reformation in 1517 and split the church in two -- came to him in a moment of relief from a particularly uncomfortable bout of constipation.
The joke arose due to the proximity of Luther's second-floor study, in Wittenberg's old Augustinian monastery, to the communal bathrooms.
But whether it was intended to discredit him or not, the metaphor is apt for the following shakeup of an overly indulged Holy Roman Empire, which changed the course of European history.
Visitors can speculate on the validity of the rumor firsthand at the Luther House, which has been a museum since 1883 and is the world's largest to highlight the history of the Reformation.
Emperor Qin's Terracotta Warriors and Horses Museum.
Mausoleum of First Qin Emperor (China)
The mausoleum of Emperor Qin Shi Huang, who unified China from 221 to 207 BC, is best known for the 8,000 terracotta soldiers discovered within.
But few are familiar with the gruesome back story.
Its construction, which took place over 38 years, was documented by the contemporary historian Sima Qian, whose outlandish claims that 700,000 workers were mobilized to complete it actually seemed justified when the 20-square-mile necropolis was eventually discovered.
Incredibly, only 10% of it has been excavated.
Qian also claimed that mercury was used to simulate the hundred rivers of China, which may explain why high levels of the liquid metal were found in the soil above and, more shockingly, that its craftsmen were walled up inside to protect the secret of its location.
Today the location is no secret and is open to tourists.
Located at the northern foot of Lishan Mountain, the mausoleum is 35 kilometers northeast of Xi'an, in Shaanxi Province.
National History Park, Citadel, Sans-Souci (Haiti)
On January 1, 1804, the French island colony of Saint-Dominique was declared a republic and its name changed to Haiti.
After nearly 15 years of war, the first nation founded on a slave rebellion had already defeated three colonial superpowers: France, Britain and Spain.
Just three years later the country was torn apart by a power struggle between two lieutenants of its rebel army, Alexandre Petion and Henri Christophe.
The self-proclaimed King Henri I built the Citadel La Ferriere and Palace Sans-Souci in the north with money made from confiscated sugar plantations and the blood of hundreds of workers.
Perched atop a 790-meter-tall peak, the Citadel was the most impressive defensive structure in the Americas and the Palace Sans-Souci matched the splendor of any in Europe.
Henri ruled until 1820 when, facing illness and the prospect of a coup, he killed himself with a silver bullet.
Designated a World Heritage Site in 1982, this large fortress, located about 17 miles south of Cap-Haitien, is today one of Haiti's most popular tourist attractions.
Lumbini, Birthplace of Lord Buddha (Nepal)
So many sites of historic importance are steeped in violence -- memorials to the fallen, monuments to victors, holy places pulverized.
Not Lumbini, which marks the birthplace of Prince Siddhartha Gautama, who would later become Buddha.
The account of his birth is equally sedate: his mother Queen Maya Devi delivered him while resting in the shade of a sal tree on her way through Lumbini.
Three hundred years later in the 3rd century BC the Great Indian emperor Ashoka commemorated the site as the origin of a religion that transformed him from bloodthirsty warlord to benevolent dictator.
Today, Lumbini is a popular destination for Buddhist pilgrims who seek out the archaeological remains associated with Gautama's birthplace.
This includes Lumpini's ancient Mayadevi Temple, which overlooks modest lakes and quiet gardens.
Royal Palaces of Abomey (Benin)
The Royal Palaces of Abomey aren't all that palatial, but their history is certainly intriguing.
The Royal Palaces of Abomey, a UNESCO-listed complex in Benin, is an unassuming cluster of 12 two-story buildings decorated with simple yet beautiful carvings.
Its heritage is more elaborate.
Once the capital of Dahomey, it was founded by King Wegbaja at the beginning of the 17th century.
It was said that he built his palace on the grave of a rival chief "Dan" giving the kingdom the name Danhome -- "in the belly of Dan."
A unique guard of celibate women who lived alone in the palaces defended Abomey -- the only verified amazons in world history.
This all-female force numbered 6,000 at its height and was taught to fight from childhood.
They were battle hardened, merciless and terrorized their neighbors.
This African Sparta fought heroically to maintain its independence, which it managed until 1894, when it was finally colonized by the French.
Head Smashed in Buffalo Jump (Canada)
From the highest point it's no more than 10 meters to the bottom of this cliff face in the Porcupine Hills of southwest Alberta, Canada.
The buffalo remains go deeper -- 12 meters of bone deposits line the base -- evidence of a unique hunting practice carried out over 6,000 years by the indigenous Blackfoot tribe.
Blackfoot buffalo runners would dress in wolf skins to frighten herds toward a precipice.
The weight of numbers forced the animals to jump and break their legs at the bottom, where they were easily dispatched and carved up for food.
According to legend a young Blackfoot hunter wanted to watch the falling Buffalo from the foot of the cliff but his curiosity was crushed by the weight of dozens of animals landing on top of him, causing his head to cave in and giving the place its name.
Located outside of the town of Fort Macleod, the site was added to UNESCO's World Heritage roster in 1981.
Today, visitors will find an interpretive center, remains of marked trails, an aboriginal camp and plenty of buffalo skeletons.
Agra Fort (India)
The vast fort at Agra was the seat of power for the Mughal emperor Akbar "the great," who justified his name by extending his empire over most of the Indian subcontinent, marrying a Hindu (the Mughals were Muslims) and promoting religious tolerance.
Akbar employed 4,000 men to renovate the existing fortifications in 1558, transforming it over the next eight years into a leviathan of red sandstone.
Today this crumbling citadel, replete with intricate marble palaces, is often overlooked as a footnote in the tale of its more illustrious neighbor, the Taj Mahal.
Shah Jahan, Akbar's grandson, famously built the Taj as a memorial to his beloved wife, who died in childbirth.
But toward the end of his life he was imprisoned in the fort by his ruthless son Aurangzeb -- fated to watch over his wife's tomb until finally, he too was interred there.