This model of modernity and progress is now again at the forefront of China's efforts to further open up as Shenzhen leads the development of the Guangdong-Hong Kong-Macao Greater Bay Area.

In Edinburgh, the spirit of innovation is also deeply rooted, the blossoming shoots of that being its prowess in financial services, software engineering, data science and renewable energy, says Jim Galloway, founding director of the consultancy Edinburgh Global Limited and a former head of enterprise and innovation with the City of Edinburgh Council.

The Scottish Enlightenment of the 18th century produced intellectuals such as Adam Smith, the father of modern economics, who revolutionized the idea of society, trade, religion and more, and Edinburgh was widely called the Athens of the North, Galloway says.

Donald Wilson, a former lord provost of Edinburgh, talks of Edinburgh's reputation as a festival city, with 11 major international festivals taking place there last year.

The Edinburgh Festival Fringe last year featured more than 3,300 shows from 58 countries and regions, infusing the city with fresh creativity amid the cultural intermingling.

"So you see the reason why the two cities admire each other," Wilson said. "In Shenzhen it's very easy to see that it is looking forward very quickly all the time. Edinburgh is an ancient historic city, but it has always prided itself on moving forward."

In 2013, Wilson signed a memorandum of understanding with Shenzhen on creative industries, something with which both cities thrive. Shenzhen is recognized as a UNESCO City of Design, and Edinburgh is the founding city of the UNESCO Creative Cities Network.