When foreigners make their lists of what to see and do in China, it's a tough call. With historical overload rife in the middle kingdom, ancient sites and treasures are virtually a dime a dozen. And then there is Xi'an.

Possessing a historical pedigree that defies description, there is much underfoot in Xi'an. Standing in the downtown Bell Tower trying to make sense of it all on a dusty evening, it's not difficult to imagine the city in its former incarnations, a city that once competed with ancient Rome and Constantinople in the Byzantine Empire to become the world's supreme metropolis.

 Stretching out from each major point of the compass, main roads disappear into the horizon. Four arterial routes, one tower hub – what could be more logical than creating easy access on an axis. 

For all the places those four roads take visitors and the subsidiary reasons people visit Xi'an: the finger of Sakyamuni, the city wall, and the foot of Lishan Mountain where Kuomintang leader Chiang Kai Shek was captured in 1936, ending 10 years of civil war, visitors are really in the city to see one thing and one thing only.

It would be an understatement to say Emperor Qin Shihuang (First Emperor of the Qin Dynasty - 221 B.C.-206 B.C.) led a full life. His list of achievements included uniting the country by defeating countless tribes, creating a uniform currency and script and starting the construction of what became the Great Wall. Quite a CV! Yet what the eccentric emperor is best remembered for is how he prepared for his journey into the next world.

They stand in honor of their departed emperor, now more than 2,000 years after his death, brick red guardians, each unique, each silent. The Terracotta Army changed Xi'an irreversibly. Discovered by farmers in 1974, the cavernous main vault is home to more than 6,000 life-size pottery warriors, chariots and horses arranged as the main force of a battle formation. Two other vast vaults, currently under excavation, make up the flank force and military headquarters. It's impressive. UNESCO thought so too, naming it a World Heritage Site in 1987. Today it has spawned an industry like no other and has put Xi'an firmly on every traveler's map. Warrior souvenirs are available everywhere in Xi'an, and are made into everything from ice-creams to the male mannequins gracing designer shop windows.

Walking over the sizable grounds around the vaults – and trying desperately to block out the incessant blare of tour guide bull horns and the jostle of endless crowds – thoughts inevitably turn to what must still lie below one's feet.

Tour guides will tell you that while more than 4,000 historical sites and tombs have been excavated to date around Xi'an, more than 120,000 relics remain unearthed. Cities built upon cities for over 3,000 years and through 13 dynasties means what we see here is in all probability just a glimpse of a much bigger picture.

This is an analogy for the Chinese tradition that encourage individuals to keep a low profile. The whole notion of staying among the crowd and doing nothing to be noticed goes back millennia, and in a sense, cleverly buries much in both the process of communication and in conveying any sign of success. Taoist founder and influential thinker Lao Zi advocated the early retirement of people once they had achieved success, marking a smooth transition from fame to obscurity. As he wrote in Tao Te Ching, "The Tao that can be named is not the Tao." Understanding this, the insight of experiences cannot always be expressed. This gives way, in a philosophical sense, to a kind of vagueness in China that characterizes tradition (certainly among the middle-aged and seniors) and is epitomized by a well-known Chinese proverb that says, "The big tree is more easily blown down by the wind."

Going about one's daily affairs quietly, not attracting attention and remaining below the radar, is probably a good way to ensure self-preservation, for whatever reason, and there are no doubt many. And it is for this reason one gets the impression that so much of Chinese culture is tantalizingly out of sight. What we see is a tip of the cultural iceberg, where things are implied but never directly stated and a smile or a "maybe" is often the answer to questions. The subtleties of flowing with this takes some time to get used to as a foreigner, particularly as so much of our thinking is based on a "yes" or "no" approach.

Just as in Xi'an, there will always be mystery in what we cannot see and whether it's yet to be discovered treasures or unfathomable cultural intricacies, in China there is much that remains beneath the surface.