Britannia Manor is the residence of game designer Richard Garriott. The name comes from the castle of Lord British, ruler of Britannia, the setting of the Ultima computer role playing game series, which he created. Britannia Manor is situated atop a large hill near Austin, Texas. The home was featured in a 2007 episode of the HGTV television series, Secret Spaces, on Lifestyles of the Rich and Famous, and on MTV Cribs.
The manor's medieval design reflects Garriott's interest in the era. The house is adorned with various medieval items such as crossbows, swords, and armour. It features traps and a network of secret passages and rooms. A secret room in the basement contains some of Garriott's most treasured artifacts, including dinosaur fossils, a coffin with a human skeleton inside it, and an authentic 16th century vampire hunting kit. The house also features other collections such as hairs from the Glacier snowman, a brick from the Great Wall of China, a Russian spacesuit, and three stained glass windows retrieved from an abandoned church. There is a large collection of automatons.  The basement room he refers to as the dungeon, has shrunken heads, mummified remains of parts of people as well as a mummified bird found in a tomb in Egypt, and human skulls. 
The house also has an observatory in the main complex. Although part of the house, it is structurally independent from the rest of the house in order to damp out vibrations, as they ruin long-exposure space photos.
Britannia Manor was designed by designer/architect, Alan Barley, of Barley & Pfeiffer Architects in Austin, Texas. In 1996, Garriott hired Moore-Andersson Architects, Austin, to design another house on a nearby riverfront property. The property is situated atop a bluff overlooking the Austin, Texas skyline, the 360 Bridge, and Lake Austin. Britannia Manor Mark 3 will also have a rotating observatory and will be more castle than house. Construction on this house was delayed for some time after the dot com crash. It resumed for a while a few years later, but was put on indefinite hold when Garriott decided in 2008 to spend the majority of his fortune to go into space.
There is a working cannon at the front door and an indoor grotto with hot-and-cold-running rain showers.
Before 1995, Britannia Manor was famous for hosting the most elaborate haunted house in the US. Garriott spent a great deal of money biannually around Halloween to pay for makeup, tools, construction materials, special effects, and costumes for his haunted house. The actors and techs were all volunteers, many donating hundreds of hours for the honor of being a part of the show, and a free t-shirt. Only two men were paid to work on Britannia Manor, Greg Dykes and Keith Ewing, from local construction company Custom Creations. They oversaw and organized much of the specialized set construction. Invitations to what Garriott thought of as a giant house party were given away free, with the exception of a few shows where tickets were donated to charity and sold for $100 or more. People waited for as long as two weeks, camped out in front of Garriott's house, to be first in line to receive the free invitations.
Britannia Manor was a full contact Halloween adventure. The events were designed like a role-playing game. Participants would go through Garriott's mountain property in adventuring parties, gathering clues to solve mysteries and quests, while facing different perils and pitfalls. The actors would touch, grab, and physically as well as verbally interact with the guests, who could not simply wander through like in most haunted houses. They would have to swing, crawl, climb, and row their way out. It was not uncommon for parties to lose members in the course of the quest.
The format of an interactive full contact haunted adventure that Richard Garriott created has continued to this day. Many of the volunteers who worked on Britannia Manor, including Keith Ewing, formerly of Custom Creations, transferred Richard's ideas and their talent and enthusiasm to support the Wild Basin Wilderness Preserve in Austin for nine years from 1996 to 2005 by creating Wild Basin's Haunted Trails. In 2007, many of those volunteers supported SCARE for a CURE, a charity haunted house in the Austin Elk's Lodge directed by Jarrett Crippen, aka The Defuser. SCARE for a CURE has now incorporated as a non-profit.
In 2009, SCARE for a CURE, now sponsored by Richard Garriott but still under the direction of Jarrett Crippen, was held in Garriott's unfinished manor about half mile from the original manor, which he has dubbed Britannia Manor Mark 3 (Mark 1 being his original house in New Hampshire, and Mark 2 being his current residence).
On the waterfront portion of the property, Garriott has built a scaled replica of an Elizabethan outdoor theater called the Curtain, after the original Curtain Theatre. Capable of seating well over a hundred, Garriott's Curtain theater is modeled after the style also replicated in full-scale by Sam Wanamaker's Globe Theatre replica in Southwark, on the south bank of the Thames, in an area known as Bankside.
A free documentary was also made called The World's Most Famous Haunted House: A Tribute to Britannia Manor.
- Video Tour of Britannia Manor
- MTV Cribs Britannia Manor
- "CNET TV | Video Product Reviews, CNET Podcasts, Tech Shows, Live CNET Video - CNET TV". Cnettv.cnet.com. Retrieved 2012-08-18.
- Mini documentary on the history of the Britannia Manor haunt
- Posted 7/6/07 (2007-07-06). "Britannia Manor: Tales From The Crib | News Video". MTV. Retrieved 2012-08-18.
- "Automata Collection - Martha Stewart Holidays". Marthastewart.com. Retrieved 2012-08-18.
- "Richard Garriott's House - Britannia Manor - a peek inside by Bizarre Magazine". YouTube. Retrieved 2012-08-18.
- Do You Want to Play?
- Custom Creations Company History page
- Austin Chronicle Haunted Trails Review 1997
- [dead link]
- AGDC 2007: Inside Garriott's Playground (2007-09-06). "The Escapist : AGDC 2007: Inside Garriott's Playground". Escapistmagazine.com. Retrieved 2011-11-02.
- Complete description of Britannia Manor Haunted House in 1988
- Complete description of Britannia Manor Haunted House in 1994
- New Britannia Manor Mark 3 under construction on Google Maps
- Cnet shows the documentary titled The World's Most Famous Haunted House: A Tribute to Britannia Manor