"I'M SORRY, you can't take these seats," the manager said as we sat down wearily at the end of a long table in a tea house in the mountain town of Bndaling, with copies of ancient Chinese scrolls hanging on the walls. "They are reserved for a coachload of Japanese tourists."
So we moved and watched from a corner as the waitresses bowed and smiled at the perspiring travellers from Tokyo when they arrived draped in Nikon cameras and American T shirts.
The Japanese may not be the most popular people in China, where there is currently an upsurge of anti Japanese patriotism over disputed islands, but when it comes to tourism, business is business. And tourism is booming in China right now.
Three thousand feet up in the mountains of Yanqing County, north of Beijing, Badaling is the most popular site for viewing the Great Wall, the 6,000 km stone barrier built many centuries ago to keep out marauding bands from the Gobi desert and which is now one of the world's great tourist attractions.
Unlike the Berlin Wall, it never actually served as a real boundary between peoples, and did not figure in any epic battles, but its beacon towers were useful for spotting enemy movements and sending smoke signals by burning wolf dung, and its surface was a handy means of transporting troops and equipment.
As one of the celebrated ancient artifices in China, the wall has helped lure world travellers back to the communist state in greater numbers than at any time since the tourism trade shrivelled up after Tiananmen Square in 1989.
Where once the visitor had to bring his own packed lunch, there are now dozens of Chinese style fast food stalls selling chicken and rice, and fried leek and egg dumplings. There are ice lollipop carts everywhere, and several bored and tethered camels serving as props for holiday albums. Beneath the wall there are alleys of trinket and junk shops like an Arab souk.
Its latter day popularity has created traffic problems. The winding mountain road up to the official entrance onto the wall from the town of Changping is almost permanently jammed with tour buses and cars full of sightseers. Built wide enough to take five horsemen riding abreast, spears at the ready, the wall at Badaling now takes an army of tourists 12 abreast, cameras in hand.
For mile after mile, up and down the hot stone slabs, over the peaks and through the cool, gloomy arches of the watch towers, the wall is as busy as Grafton Street on a Saturday afternoon. There are Japanese, Americans, Koreans, British, Australians - people of every nationality. But the vast majority are Chinese.
It wasn't always so. Only 25 years ago, when the Cultural Revolution was raging, the Chinese were randomly wrecking bits of the wall as a symbol of a discredited past, and peasants were hauling off stone tablets to use as home improvement aids. During those anarchic days, army units stripped sections to build barracks.
But the economic reforms have changed the outlook of the nation, creating a middle class and a generation of Chinese not burdened with the struggle to survive and intent on sight seeing in their own country.
It is big business. Every person who walks on the surface has to pay the equivalent of £1. Foreigners, overseas Chinese and "compatriots from Hong Kong, Macau and Taiwan" pay £2.50.
This coming weekend a new Great Wall Expressway will be opened to bring traffic more quickly along the 70 km route from Beijing to Badaling. The only thing then stopping the wall at Badaling being completely overrun will be the traffic jams on the mountain road from Changping - where those who cruise out of the city on the new toll road will actually spend most of their afternoon.
Far better to find a less popular stretch of wall, like that at Mutianyu further to the east, parts of which, as we discovered after climbing through woods of chestnut and crab apple trees, is even more spectacular and rewarding, and completely deserted - except for a guy collecting the "walk on" fee.