Example nginx.conf for custom error pages

nginx-error.conf

server {
    listen 80;

    server_name HOSTNAME;

    root /opt/PATH/;
    index index.html;

    rewrite ^/$ /en/PATH/ redirect;

    error_page 403 /403.html;
    error_page 404 /404.html;
    error_page 500 /500.html;
    error_page 502 /502.html;
    error_page 503 /503.html;
    error_page 504 /504.html;

    location / {
        try_files $uri $uri/ index.html;
    }

    location ~ /([0-9]{3}).html {
        try_files $1.html @error;
        internal;
    }

    location @error {
        root /opt/error-pages;
    }
}