Xinjiang: On the new frontier
(CNN) -- It's what the Xinjiang resident couldn't say that said the most.
"I can't talk about that," he said nervously. "Bad things. If I talk about bad things, then there will be trouble, I hope you understand."
Human rights groups refer to the situation in Xinjiang as China's "other Tibet".
The town is Kashgar -- a name that conjures up romantic images of camel trains on the old Silk Road between Europe and China.
This ancient desert oasis is where Marco Polo stopped on his way from Venice to the Chinese imperial court.
Until recently it hadn't changed much. Kashgar is still one of the most important trading centers in Central Asia -- much as it was in Marco Polo's time.
Every Sunday Kashgar's population swells by the hundreds of thousands as ethnic Kazakhs, Kyrgyz, Tajiks, Turkmen and even a few Afghans mingle with the native Muslim Uighur population to trade animals and produce, swap stories and drink endless cups of tea.
But today the old Kashgar is disappearing fast.
The "bad things" my friend refers to include the break-up of established communities; the demolition of yellow adobe homes that for centuries have formed the bedrock of Uighur society; and the strict government control (critics call it repression) of Islam.
According to human rights groups, even talking about these "bad things" can land you in jail -- or worse.
Groups such as Amnesty International and Human Rights Watch say thousands of Uighurs have been detained and unknown numbers executed in the name of anti-separatism and, more recently, counter-terrorism.
"Bad things" are not the face of Kashgar the Chinese government wants visitors to see.
Technicolor tourist posters show smiling locals in dazzling ethnic costumes, standing amid lush green pastures and soaring snow-capped mountain peaks.
Except, more often that not, the faces of the 'locals' aren't Central Asian -- they are Han Chinese, the dominant ethnic group in the People's Republic of China, but until recently a tiny minority in the far west of the country.
Kashgar is located in the southwest of what China calls the Xinjiang Uighur Autonomous Region -- a largely desert area three times the size of France with a population about the same as that of Shanghai.
For comparison, Shanghai has an area of about 6,340 sq km. Xinjiang is more than 1,600,000 sq km.
But what Xinjiang lacks in population, it more than makes up for in resources. For one thing, it has lots space -- a valuable commodity in a country as crowded as China.
More valuable still, it has oil, gas, countless other mineral resources, and some of the most fertile land in China.
The name Xinjiang translates as new frontier -- and in many ways Xinjiang is seen by the Chinese government in the same way as California and the Wild West was in the early days of the United States.
Government-backed resettlement programs and the steady encroachment of new rail lines are bringing thousands of Chinese from China's overcrowded east to Xinjiang.
From the government's perspective and that of the migrants, they are bringing money and progress to an underdeveloped region.
Certainly education standards have increased, as have literacy levels -- but it's literacy in Mandarin Chinese, rather than the traditional Turkic-based languages.
Education in Uighur Muslim culture and local language is strictly controlled
"We don't like them (Han Chinese)," says one Kasghar taxi driver. "They eat pork and that's forbidden in Islam. But they don't like us either."
In 1949, Uighurs made up about 90 percent of Xinjiang's population. With the influx of non-native Han Chinese, that proportion has plummeted to 45 percent and is falling still further.
These "bad things" are what is happening to his city, one of the oldest and most evocative in Central Asia, and modern China's most westerly outpost.