This time on Watercolour Challenge, Fern invites four would-be painting champions to one of Yorkshire's grandest of all grand houses. Castle Howard, in the north of the county, is a 300-year-old architectural masterpiece designed by John Vanbrugh. It sits in nearly 9,000 acres of spectacular grounds, is still occupied by the Howard family who commissioned it centuries ago, but is perhaps most famous as being the location for Brideshead Revisited. The artists' view today is of the formal gardens sweeping towards the Atlas Fountain with the fantastic house behind. It's a challenging view, with potential composition and perspective pitfalls that could fox even the most professional eye! Judging the paintings today is internationally acclaimed army veteran-turned-painter Ady Wright. He gives some tips along the way, including a simple way of demonstrating depth using different tones of the same colour. As the painters take to their easels, Fern meets Nicholas Howard, the current family resident, to discover how his trail-blazing ostentatious ancestors employed the greatest architects of the day to embed a piece of Italy into the North Yorkshire landscape. Castle Howard also has a significant art collection, and we meet one of its curators to discuss perhaps the greatest piece in the house, a magnificent fresco painted by the fashionable Italian artist Antonio Pellegrini at the turn of the 18th century. In this awe-inspiring location, which of the four amateur artists can rise to the challenge?