James Antrobus/Flickr
One of the first things you notice when visiting Hong Kong is its hilliness. Then you notice the escalators running up those hills.
The city is home to the longest outdoor escalator system in the world - the $4 system. The escalator system was built in 1993 as a solution to the massive traffic congestion in the city.
Even though it's received some criticism because of its high cost and inefficiency, it still stands today $4.
Take a look inside.