Nginx domain path issue

Solution 1:

You need to externally redirect / to /parks/fairgrounds/ in the second server block.

Try:

server {
    listen 80;
    server_name example.com;
    return 301 https://$host$request_uri;
}
server {
    listen 443 ssl http2;
    server_name example.com;

    ...

    location = / {
        return 301 /parks/fairgrounds/;
    }    
    location / {
        ...
    }
}

The first location block only matches / and externally redirects visitors to https://example.com/parks/fairgrounds/. The second location block is your existing location block, and handles everything else. See this document for details.