The exterior of Mayfield Psychiatric Hospital was seen briefly near the end of the season 5 finale Both Sides Now. House suffered from psychosis, when he realized he had never slept with Cuddy nor had he detoxed at all. Then he and Cuddy went to see Wilson. Afterwards, intercut with Cameron and Chase's wedding, we see House and Wilson go to Mayfield Psychiatric Hospital. House, carrying a suitcase, goes in willingly without saying anything to Wilson.
In Season 6, House is willingly living in Mayfield Psychiatric Hospital. He can leave anytime he wants but his medical lisence is in danger. Dr. Nolan is Houses doctor and must diagnose him in an attempt to allow him to keep being a doctor.
Exterior shots of Mayfield were taken at the abandoned Greystone Park Psychiatric Hospital in Parsippany-Troy Hills, New Jersey. The hospital was opened in 1876 and closed in 2008 when another modern facility was built to replace it. Before it was closed, it was largely abandoned.
Mayfield Psychiatric Hospital is going to be a major location during Season 6.