1337x proxy servers are perhaps the simplest way to get to the site. A proxy server is a server that acts as a middleman between clients and other servers when they request resources. Outside observers only see that you're connected to the proxy server when you use a proxy server to access 1337x; they don't notice that the proxy server is relaying data from 1337x to you.

It's common to mix up 1337x proxy servers and 1337x mirrors. A 1337x mirror is a clone of the original site with a different domain name and server architecture than the original. A 1337x proxy server, on the other hand, is a distinct website that allows users to access both the original 1337x and other websites.
In truth, it doesn't matter whether you connect to 1337x using a proxy server or a 1337x mirror; both give a same level of protection.