Less remarkable for its tourist attractions than for its proclivity for commerce, Dongguan is the most productive county in the Pearl River Delta. Bargain hunters revel in Dongguan's proximity to factories and warehouses, as prices for anything from electronics to fashion items, bedding, pirated DVD's (much to Beijing's ineffectual consternation) and computer software (despite periodic threats of trade sanctions) can often be negotiated to nearly wholesale prices - even for single items.
Commercial activity rules here, but if you've ever had a morbid curiosity to see what a commercial dystopia looks like, look no further than Dongguan's South China Mall, the world's largest and emptiest commercial complex. Though this mall features a couple kilometers of man made river, complete with touring gondolas, rides for children, a miniature Arc de Triomphe and seven zones modeled on: Amsterdam, Paris, Rome, Venice, Egypt, the Caribbean, and California, it is still a sprawling ghost town. But it's actually worth seeing if just to experience the unsettling juxtaposition of monstrous hyper-kitsch replicas with the skein of ghastly quietness that engulfs them.
For the honest tourist, Dongguang's pickings are a little on the slim side, but there is still enough to see and do to pack a couple of full days. Dongguan's importance in the Opium Wars necessitates the presence of several museums. To brush up on this interesting part of China's history you'll want to check out the Opium War Museum, as well as the Humen Naval Battle Museum.
Dongguan also has a few spots of leaf and shade to relax in, and there is even a mountain to climb. First on the list is the centrally located Keyuan Garden, one of Guangdong's historic "four famous gardens." Though "Keyuan" literally means "a garden not too bad for visiting," the place considerably outshines its name - which is the product of builder Zhang Jingxiu's legendary modesty. You'll no doubt be impressed by the site's labyrinthine layout, and have the opportunity to relax among the leaves, orchids and shade that shelter visitors from the metropolitan cacophony outside. Also worth visiting is the picturesque Yingxian Resort, a little further out at about 15km (10mi) from the city. Offering dense forests, endless mountain vistas, a host of temples, and a 2,000 ton white marble statue of Kwan-Yin (China's Goddess of Mercy), Yingxian makes for a good full day excursion.
To finish up before moving on to nearby Guangzhou, Shenzhen, or Hong Kong, you can try taking a stroll on the Humen Bridge at sunset to take in panoramic views of the city below.