A Ring Base is a facility used by The Ring to carry out their various illegal activities. There have been three noticeable bases used by them to date. The first is the base seen in "Chuck Versus the American Hero" when Shaw handed his self into the ring, the next being the base in "Chuck Versus the Other Guy", which Sarah, Chuck and Shaw broke into to capture the Ring Director and finally the base seen in "Chuck Versus the Subway" which Chuck and his father break into to try and stop Shaw.
Base in American Hero Edit
The base seen in this episode was completely based underground with the only passage in and out being a futuristic lift, activated by punching a certain drinks order into a coca cola machine. Shaw was taken to this base for what he thought was a face to face meeting with the ring director, but it turned out the director was using a hologram and wasn't actually at the base.
In this talk with Shaw was when it was revealed that Sarah had been the person who killed Evelyn Shaw, which Sarah did for part of her CIA Red Test. Shortly after this was revealed Shaw was knocked unconscious at the same time as Chuck arrives at the base. Chuck finds Shaw and drags him out of the base just in time as the bomb strike on the base, that Beckman ordered destroys the base.
Base in Other Guy Edit
In "Chuck Versus the Other Guy" Chuck, Sarah and Shaw infiltrate this base in an attempt to capture the director of the ring who is based at the facility. Whilst Shaw hacked the directors file, Sarah and Chuck break into it and surprise the director, attempting to force him to leave with them. Chuck and Sarah confront the Director, who reveals that the Ring has developed its own prototype of the Intersect Cipher, and carefully manipulates the situation to create a Mexican standoff between Sarah, Chuck, and two of his operatives.
He then reveals that they have walked into a trap when several additional Ring agents arrive and force Chuck and Sarah to stand down. Shaw arrives and kills the Director's men, and offers to cover their withdrawal while he retrieves the Cipher. The elevator doors close, leaving Chuck and Sarah outside as they hear a gunshot. However, after they leave the facility it is revealed that the entire incident was staged by the Director, and Shaw has in fact joined the Ring.
Base in the Subway Edit
In "Chuck Versus the Subway" whilst on the run from Shaw,Chuck and his dad, using directions from Ellie, find and infiltrate the ring's headquarters. Like most ring bases it's underground and requires a longish walk to get the secret entrance. The front door of the base is hidden but Chuck and his dad find the way to open it but accidental trigger a silent alarm. They are soon joined by Shaw and his body guards who when Chuck challenges to a fight of the Intersect, promptly kills Chuck's dad in order to make Chuck loose his calm.
This Ring base is most likely the Ring's main, or at least one of there top bases, as it contains two very important pieces of equipment. These important gadgets would the the Ring's Intersect room where there Intersect, known as the Ring Intersect is stored and where people are uploaded with it. This would make the base an Intersect building.
The other important pieces of equipment is the Ring's state of the art lab which contains a doctor's research and equipment that is able to bring people back to life after they have died. We find out at the end of the Chuck's third season that this lab was used to bring Shaw back from the dead. It could be assumed that this device is able to bring people back to life after a long time as Shaw was in France when he died and so had to be transported back.