error_page 404 error/404.html;
location = error/404.html {
    internal;
}

location = robots.txt {
    allow all;
    log_not_found off;
    access_log off;
}

location = explore/ {
    index index.html
}

location ~* explore/(.*)/ {
    if ($request_uri ~ ^/(.*)\.html) {
        return 302 explore/$1/;
    }
    try_files $uri $uri.html $uri/ =404;
}
}