It’s the Vancouver seawall, of course – No. 6 in Lonely Planet’s 10 best hikes within an urban area:
If you want to see the best of Vancouver, you need barely stray off the 22km seawall. … If you need to shorten things, consider the 9km section around Stanley Park – the sunsets are just as good from the logs on Third Beach.
The City of Vancouver website has a seawall map here.
No. 1? Tijuca Forest, Rio de Janeiro.
And yup, that seems right:
Brazil’s first national park, the world’s largest urban forest, smack bang in the heart of Rio de Janeiro.