Dressed in our summer finest, we wait in Amberley Castle’s grand reception hall until a crisply-suited waiter approaches and leads us off on an adventure through the grounds of this multiaward winning country castle hotel to our dining location – Mistletoe Lodge Tree House.

We walk under the two tonne oak portcullis and out into the 12 acres of beautifully-landscaped gardens and head towards a mighty poplar tree by a small lake.

In the golden, late-afternoon sun, we can just about make out the silhouette of a small wooden structure high in its boughs. As we approach, our waiter reveals a bottle of Champagne and two cold glasses. “Welcome to Mistletoe Lodge Tree House where you will be dining tonight,” he announces.

We are invited to stroll over a small bridge and sit on a wooden swing chair overlooking a peaceful lake where we are served chilled Champagne.

The waiter explains our three-course meal and wine awaits us in the tree house above. We have exclusive use of this charming olde worlde den for the entire evening, so he bids us farewell and asks that we return to the hotel before dark.

We sit calmly until the waiter is only a dot in the distance, then guzzle our Champagne, kick off our shoes and run to the tree house. It’s hard to explain the childlike excitement which grips you when faced with your very own tree house. For me, it involves memories of Enid Blyton’s Magic Faraway Tree mixed with Tolkienian fantasies.

We bounce along a rope bridge then climb chunky wooden stairs which curl around the trunk and deliver us to the heart of its sturdy branches. Inside, the tree house is rustic but cosy. A table for two is set beneath the window and the room is light and surprisingly cool.

Guests pre-order from a set menu of cold dishes – on a warm and fragrant summer night, hot dishes aren’t really required.

The menus change to reflect the season but starters include the likes of smoked salmon, apple, pea shoot salad and lime dressing, and wild leaf and sheep’s milk salad with cured

tomatoes and pata negra ham. Our three main course options were fresh local lobster with a thai noodle salad and tom yung spiced aioli, roast duck and peach salad with new potatoes, and caramelised onion and goat’s cheese tart with tomato pickle and leaf salad.

The highest-quality ingredients ensure fine flavours and wholesome textures right up to dessert. The strawberries are fresh, sweet and ripe and the clotted cream and vanilla citrus syrup provide a splash of naughtiness.

After dining, we retire to the balcony area to watch the spectacular sunset over The Downs. The cost is rather daunting (£195, excluding hotel accommodation which starts at £165 per night) but for a special occasion or a romantic surprise, it is hard to think of anywhere more perfect.

■ Available May to early September.