Flying through Beijing or Shanghai and fancy a stopover to explore either city? China's new 72-hour transit visas — available free, on arrival at the airport — let you enjoy a three-day taste of two of the country's most interesting metropolises.

Australia and New Zealand citizens are included, along with more than two dozen other countries.

Under previous arrangements, which remain in place for the rest of China, every visitor to Beijing and Shanghai needed to hold a valid visa based on the purpose of their visit, such as business or tourism.

However, note that these are transit visas which can be used only during your travel from one country to another country via Beijing or Shanghai: you can't use them to fly from Sydney to Beijing, for instance, and then back home again.

And you're not allowed to leave Beijing Municipality or Shanghai Municipality without applying to the Public Security Bureau.

Check out the full list of rules from Beijing Airport, and check with your airline before travelling.

A few of our favourite things to do in Beijing and Shanghai

In Beijing, we reckon the Mutianyu section of the Great Wall is the perfect mix of attractively reconstructed and not swarming with tourists. Avoid swamped Badaling, but consider also the more remote Simatai. (Note that all three are within Beijing Municipality, where you must remain as a condition of the transit visa.)

If the weather is decent, try the day's walk from the south end of Tiananmen Square north, through the Forbidden City, up and down Jingshan Hill, then bearing left towards the ornamental lakes. See if you can find any traditional hutong dwellings left between Beihai and Dianmennei Dajie. End up at the bars on Houhai.

And if you have an absolutely sky blue day by some miracle, head out to the Fragrant Hills and take the chair lift up to the top for a panoramic view across the whole of Beijing. Don't forget your camera.

If you're visiting Shanghai, the maglev from Pudong airport is hard to resist. Hitting 431km/h as it rockets along 30km of track in barely 8 minutes, there's just enough time to contemplate what a two-hour maglev journey between Sydney and Melbourne would be like!

Once you've settled into the city, relax with a sunset drink at one of the rooftop bars on The Bund, overlooking the glittering Pudong skyline across the river

Our favourite is still Shanghai institution M on the Bund (M is for Melburnian founder Michelle Garnaut) at number 5 The Bund. Alternatively, if it's clear, head up into the sky to one of the panoramic hotel bars in Pudong. Cloud 9 at the Grand Hyatt in the Jin Mao building is a good stalwart.

Got recommendations to share with your fellow AusBT readers for things to do in Beijing or Shanghai? Drop them in a comment below! 

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