Prinsengracht Canal

What is it: Prinsengracht is one of three main canals in Amsterdam (along with Herengracht and Keizersgracht) that form concentric rings around the city. They were built in the 1600s during the Dutch Golden Age when Amsterdam was the third biggest city in the world. They were designated a UNESCO World Heritage Site in 2010. The Anne Frank House is on Prinsengracht.
What's it like: The canals are a major part of modern Amsterdam and yet they retain a historic, ornamental sort of charm at the same time. They certainly give the city a very unique atmosphere. Just mind all the bikes.
Where: Amsterdam, The Netherlands
When: October 2018
How: I flew to Amsterdam and spent two days visiting various sights with my friend Kathy - we also saw the Anne Frank House (59), the Rijksmuseum (233), and the Van Gogh Museum (190). 

Worth noting: Amsterdam is known as the 'Venice of the North', with one hundred kilometers of canals and 1,500 bridges. It's well worth doing a boat tour and seeing all of the buildings from the water.
Place in the 2015 edition: 128
Did it deserve to lose its place in the 2020 top 500: I'd have put all four of the main canals and that whole area on the list - they're collectively known as the Grachtengordel - but they definitely deserve to be on there.