Nestled beside a loch in the Scottish Highlands is Inveraray Castle, a mid-18th century country house that brings in a staggering 130,000 visitors each year. Host Julie Montagu, Viscountess Hinchingbrooke travels to a remote corner of Scotland to see how its owners, the Duke and Duchess of Argyll, run their massive castle and sprawling 50,000-acre estate as both a business and private home. Julie attends the annual Inveraray Highland Games and has a go at the most challenging event: tossing the caber.

Floors Castle is the largest inhabited castle in Scotland, a massive and magnificent mansion sitting on approximately 52,000 acres of prime Scottish countryside. Julie Montagu, Viscountess Hinchingbrooke crosses the border to visit Guy Innes-Ker, the 10th Duke of Roxburghe, for a personalized tour of the castle's grandest rooms and most fascinating stories. She'll also get a lesson in table-setting from the castle's butler, try her hand at fly-fishing, and get a VIP ticket to the prestigious Floors Castle International Horse Trials.

Holdenby House in Northamptonshire was once one of the largest palaces in England and was also a prison for King Charles I in the mid-1600s. Today, it's the home of James and Karen Lowther, who over the years have invested millions on restoring it to its former glory and preserving it for future generations. Julie Montagu, Viscountess Hinchingbrooke visits the 2,000-acre estate and 75-room country house, where she gets a lesson in music, falconry, and how to keep an aging home aesthetically pleasing and profitable.

Julie Montagu, Viscountess Hinchingbrooke is a little nervous about her visit to Boughton House, and it's no surprise why. Its owner, Richard Scott, holds two dukedoms and is the biggest individual landowner in Britain. Boughton House has been the home of Julie's distant relatives and ancestors dating back nearly 500 years. Witness a unique family reunion, where Julie learns about the colorful Montagus who brought Boughton to life over the centuries, capped by a family supper hosted by Richard.

Host Julie Montagu, Viscountess Hinchingbrooke makes a trip to Gloucestershire to visit Sudeley Castle, England's ultimate fairytale wedding venue. Here, couples wander the same landscaped grounds that Renaissance royalty walked five centuries ago. Julie picks up tips on hosting weddings to take back to her estate, Mapperton in Dorset. She'll also learn about Sudeley's rich history of iconic residents, from Queen Catherine Parr, Henry VIII's final wife, to the estate's current custodian, Lady Ashcombe.

Julie Montagu, Viscountess Hinchingbrooke pays a visit to Newby Hall, England's real-life Downton Abbey. Follow her on a tour of this elegant designer show house built in the 17th century, where she meets current owners Richard and Lucinda Compton and witnesses firsthand how they preserve their designer past while finding new ways to showcase their creative heritage. Her visit concludes with the grand opening of a sculpture exhibition in the estate's prized 25-acre gardens.

Eastnor Castle is one of Britain's grandest private residences and an estate that has been home to one family for over 400 years. While the current owners honor the estate's past, they must also look towards its future to stay relevant and profitable in the 21st century. Join host Julie Montagu, Viscountess Hinchingbrooke as she visits heiress to the estate Imogen Hervey-Bathurst for an all-access look at the 97-room castle, the history of its past tenants, and the inventive initiatives being taken to meet the financial demands of modern day.