The Biltmore mansion is located near Asheville, North Carolina.  It features 250 rooms, spans 175,000 square feet, and is the largest privately owned home in the United States.  It was built between 1888 and 1895 by George Washington Vanderbilt II.  The building remains one of the best examples of Gilded Age architecture, which was the era follow the American Civil War when the population of the United States began to rise.  Today the estate sits on 8.000 acres of land and is split in half by the French Broad River.  It is controlled by The Biltmore Company, kept by Vanderbilt's grandson, William A.V. Cecil II. 

In 1956, it was opened to the public as a house museum.  It is a major tourist attraction in the U.S. and contains a 70,000 gallon indoor pool, bowling alley, turn-of-the-century exercise equipment, a two-story library, 19th century artworks, furniture, elevators, and clocks.  The grounds also contain an enormous garden, various livestock farms, a winery, and a lavish hotel.  In 2007, it was ranked eighth on the List of America's Favorite Architectural feats.

Eilean Donan is a small island located in Loch Duich in the western Highlands of Scotland.  It is connected to land by a footbridge and is very close to the village of Dornie.  The original castle was built in 1220 for Alexander II as a defensive structure against Viking attacks.  An extremely important stronghold it was controlled by the Mackenzies of Kintail in the late 13th century.  In the early 16th century Clan Matheson died while defending the castle against the Clan MacDonald of Sleat.  In April of 1719, the island was besieged by Spanish troops attempting to start another Jacobite Rising.  A month later it was recaptured and destroyed by three Royal Navy frigates.  The Spanish troops were soon defeated at the Battle of Glen Shiel. 

The structure remained in ruin for hundreds of years until it was purchased and restored by Lt. Col. John MacRae-Gilstrap between 1919 and 1932.  Construction on this building has one of two left-handed spiral staircases in a Great Britain castle.  It is one of the most photographed monuments in all of Scotland’s great history.  It is also the location for numerous weddings and has appeared in many films including The Private Life of Sherlock Holmes, Highlander, and Loch Ness. 

Urquhart Castle stands on a rocky hill on the north shore of Loch Ness in Scotland.  It is one of the most storied and important structures in Scotland’s history.  The earliest confirmed records of Urquhart Castle are from the early 1200s.  It is believed to be built by the Durward family.  In 1296, it was besieged by Edward I of England.  It was taken from the Crown in the 15th century by the Earl of Ross, but for only a short time.  In 1692, the grounds were captured by Williamite troops, but they soon realized that they could not hold off an attack by Jacobite forces.  To ensure that it would not become a Jacobite stronghold the troops purposively demolished the castle. 

They succeeded and it has remained in ruins ever since.  The stonework was salvaged by locals for reuse in the city limits.  The castle was constructed very close to water level, using Loch Ness as a natural moat.  It is now owned by the National Trust for Scotland and maintained by Historic Scotland.  It is one of the most visited attractions in the world.

Brougham Castle is located two miles away from Penrith, Cumbria, in northwest England.  The structure was originally constructed in the early 13th century by Robert de Vieuxpont.  It was strategically placed to guard the crossing of River Eamont.  The Clifford Family took control of the castle soon after that and construction was greatly expanded preparing for attacks by the Scottish.  However by the time of the English Civil War it was in bad shape and provided little protection.  It was a constant target and numerous battles were waged on these grounds. 

In 1643, Lady Anne Clifford inherited the estate and soon began rebuilding the castle.  Sadly, she died before being able to complete her vision.  It became the property of the Earl of Thanet and he didn’t care for the land.  It quickly fell into ruin as it was not maintained by English forces.  Today Brougham Castle is battered, but a very popular tourist destination.

Alnwick Castle is located in Alnwick, Northumberland, England.  It is the second largest inhabitable castle in England.  Construction on this incredible structure began in 1096 under the rule of Yves de Vescy, Baron of Alnwick.  It was the main fortress protecting England’s northern border from Scottish invasion and border reivers, medieval raiders.  It was besieged on two separate occasions by William the Lion, King of Scotland, towards the end of the 12th century.  March 29, 1461 (Palm Sunday) was a snowy, foggy, and some would say eerie day.  The House of York moved on the Lancaster factions and the Battle of Towton ensued.  This is strongly regarded as the bloodiest battle in British history.  It was a decisive victory for the Yorkists, but they controlled the castle for only a year.  Ultimately the Wars of the Roses ended in 1487 with a victory from the Lancastrian Henry Tudor, who founded the House of Tudor. 

Over the centuries Alnwick Castle has been renovated by the 6th Earl of Northumberland, Robert Adam, and Algernon, the 4th Duke of Northumberland.  Today the castle houses many special exhibitions, many featuring the Dukes of Northumberland and their interest in archaeology.  It includes some of the oldest artifacts in English history.  This castle is also the interior of Hogwarts and has been used in every Harry Potter movie.  It was featured in Robin Hood: Prince of Thieves.                     

Dunnottar Castle is located on a rocky headland a few miles away from Stonehaven, on the north-east coast of Scotland.  It is situated in a strategic location overlooking the shipping lanes to northern Scotland.  There has been a fortified structure on this land since 700 AD.  It was destroyed in the 9th century under a Viking invasion and King Donald II was killed on these grounds.  In the 12th century it became a Catholic settlement and a chapel was constructed.  William Wallace is said to have led the Scots to victory over the English at Dunnottar in 1296.  Claims have been made that the chapel was destroyed and burned by Wallace with a garrison of English soldiers inside. 

Expansive additions were made to the structure in the 15th and 16th centuries and many distinct building were constructed.  In 1650, Charles II took refuge in Dunnottar Castle for a short amount of time on his way to battle for his fathers’ two kingdoms.  This enraged Oliver Cromwell who subsequently ordered an invasion of Scotland.  A group of seventy men tried to defend the structure until Cromwell’s cannons arrived.  He demolished Dunnottar Castle and today it remains in ruins.  In 1715, the 10th Earl Marischal, George Keith was convicted of treason after the Jacobite rising and the castle was seized by the government.  The structure was neglected until it was purchased by the Cowdray family in 1925.  The ruins are spread over 3 acres of land.  Today it is an extremely popular tourist attraction. 

Himeji castle is located in Himeji, Hyōgo Prefecture in the Kansai region of Japan.  It is comprised of an amazing 83 wooden buildings.  The castle began construction under the Akamatsu family in 1346, but took its true form in the early 17th century when Ikeda Terumasa expanded the complex following the Battle of Sekigahara.  Terumasa embarked on a nine-year construction odyssey bringing the castle to its current state.  It was kept in good condition during the Edo Era, which ended in 1868.  It 1873 it was auctioned off to the public, but the Japanese military took back control of the castle in 1879.  It has been periodically renovated in modern history to repair a tilt to its base, after flood damage was sustained in 1934, and after it was bombed on two separate occasions at the end of World War II. 

Himeji Castle is a great example of Japanese defensive architecture.  Including a tall stone foundation, whitewashed walls, gun emplacements, stone-dropping holes, and a confusing maze of paths leading to the castles main keep.  It is the most visited castle in Japan and was registered as the first Japanese National Cultural Treasure in 1993. 

Alcázar of Segovia is a stone castle located in the old city of Segovia, Spain.  It was constructed on a rocky hill overlooking the rivers Eresma and Clamores.  It is renowned for its unusual shape, like the bow of a ship.  Originally an Arab fort its first historical reference is from the early 12th century.  Although archaeological evidence suggests that it might have been around during Roman times.  In the early 1200’s Alfonso VIII and his wife Eleanor of Plantagenet reconstructed much of the castle grounds.  In the Middle Ages it was the residence of the monarchs of the Kingdom of Castile and was an extremely important defense fortress. 

Probably the largest contributor to the expansion of the castle was King John II in the middle of the 15th century.  After the death of King Henry IV, Queen Isabella I of Castile was crowned leader of Castile and Leon.  Alcázar of Segovia was an extremely valuable safe haven for her.  The royal court eventually moved to Madrid and this structure was used as a state prison, a Royal Artillery College, and a military academy since then.  Today Alcázar of Segovia is a historical museum and is open to the public.

Le Mont-Saint-Michel is a tidal island located in Normandy, France.  The castle sits atop an enormous rock formation, some 250 feet in the air.  Mont-Saint-Michel originated in the 5th and 6th centuries as an Armorican stronghold of Romano-Breton culture.  In 933, William I, Duke of Normandy, annexed the Cotentin Peninsula, definitively placing the mount in Normandy.  It was an extremely important structure in the Norman conquest of England.  During the Hundred Years' War the English continually bombarded the castle, but were unable to seize it for long.  You can still see damage sustained during many of these battles today. 

The structure was controlled by The Monks of Mont St. Michel for many years and they were revered for their copying skills before the printing press was widely in use.  Gradually falling into disrepair the island was converted into a prison during the French Revolution.  This was a rather grim time on Le Mont-Saint-Michel and the echoes of battered souls are said to haunt the island.  In 1874, it was declared a historic monument by the French government.  In 1979, the Mont-Saint-Michel and its bay were placed on the list of World Heritage Sites.  The cultural, historical, and architectural significance of this island is untouched.  Today Monks live and work on Le Mont-Saint-Michel just as they did in medieval times.  During low tide the flats provide food for world's only herd of salt water plant eating sheep.

Windsor Castle is located in the town of Windsor, England in the county of Berkshire.  It is the largest inhabited castle in the world and is one of the principal residences of the British monarch.  It has been a royal palace for more then 1,000 years since the time of William the Conqueror.  It is probably the most storied castle in the world.  King Edward III was born in the structure and completely rebuilt it in the middle of the 14th century.  Elizabeth I took refuge in the castle in 1563 after the Bubonic plague hit London hard.  She had gallows built and ordered anyone visiting from London to be executed. 

During the 17th century and the English Civil War Windsor castle was a stronghold.  After being taken from Charles I it became the headquarters of Oliver Cromwell's New Model Army.  This was undoubtedly the bloodiest time for this structure.  The monarchy was restored in 1660 and Charles II began a mass expansion and restoration project on Windsor Castle.  After the death of Charles II the castle was not extensively used until George III took control.  It 1820, George IV conducted the most modern restoration project transforming the structure into a spectacular Gothic palace.  Truly one of the grandest buildings in the world certain sections are open to the public, displaying a wealth of paintings, decorative ceiling designs, antique furniture, and amazing architecture.