configuration - Help needed setting up nginx to serve static files

I'm trying to setup nginx to serve static files. Basically all I need is to have http://mydomain.com/site_media/ point to /var/django/myproject/site_media.

I have tried so many configurations and when I test it I always get a 404 error for static files.

Can anyone please tell me what I'm doing wrong or how I should be setting this up?

This is my current nginx configuration file.

user www-data;
worker_processes  1;

#error_log /usr/local/nginx/logs/error.log;
#pid /usr/local/nginx/logs/nginx.pid;


events {
    worker_connections  1024;
    use epoll;
}

http {

    # Enumerate all the Tornado servers here
    upstream frontends {

        server 127.0.0.1:8000;
        server 127.0.0.1:8001;
        server 127.0.0.1:8002;
        server 127.0.0.1:8003;
    }

    include       mime.types;
    default_type  application/octet-stream;

    #access_log /usr/local/nginx/logs/access.log;


    keepalive_timeout 65;
    proxy_read_timeout 200;
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    gzip on;
    gzip_min_length 1000;
    gzip_proxied any;
    gzip_types text/plain text/html text/css text/xml

               application/x-javascript application/xml
               application/atom+xml text/javascript;

    proxy_next_upstream error;

    server {
        listen 80;

        # Allow file uploads
        client_max_body_size 50M;


        location ^~ /site_media/ {
            root /var/django/myproject/site_media;
            if ($query_string) {
                expires max;
            }
        }
        location = /favicon.ico {
            rewrite (.*) /site_media/favicon.ico;
        }

        location = /robots.txt {
            rewrite (.*) /site_media/robots.txt;
        }

        location / {
            proxy_pass_header Server;
            proxy_set_header Host $http_host;
            proxy_redirect off;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Scheme $scheme;

            proxy_pass http://frontends;
        }
    }

    #include /usr/local/nginx/sites-enabled/*;

}

Thanks,

Cata