The first is of instant recognition of the location of Downton Abbey, the compulsive pre-First World War upstairs-downstairs series, now being repeated on Prime.
The second is at the sheer beauty of the building. Designed in 1842 by Sir Charles Barry, who was also responsible for the Houses of Parliament, it has the same ornate pinnacles on its turrets and towers, the same tall narrow windows, the same honey-coloured Bath stone.
It's elegant, impressive and stately - and, thanks to its television role, famous - but for Lady Carnarvon it's both her home and her business.
Married to George Herbert, the eighth Earl of Carnarvon, whose family have lived at Highclere since 1679, Fiona came to the castle in 2003 after her husband inherited the title. She describes this, significantly, as "taking over the stewardship": there's been a house on the site for 1300 years, which gives perspective to the comparatively brief lifespan of any one incumbent, and puts paid to grandiose ideas of ownership.
While "Geordie" runs the estate and its associated businesses, Fiona has taken on the full-time task of maintaining the fabric of the building and making the castle pay its way. That's why I'm here, joining a houseful of visitors happily trooping around three floors of the building.
The castle has been open to the public for some time, and though there's no doubt that the television series has raised its profile and increased the numbers through the gates, Fiona says the steadiest income has been from the weddings that are booked here. Starting at $19,000 for the package it buys quite a lot of lead flashing to patch a leaky roof. The estimated $2 million that model Jordan spent on her special day here, including her two pink thrones, must have been a particularly nice little earner.
Most welcome of all, however, despite the inevitable disruption to castle life, are the location fees paid by ITV for the two series already filmed and a planned Christmas special.
The house is seductively photogenic, inside and out. The high, studded front door leads into an entrance hall more cathedral than castle, its high vaulted ceiling supported by ornate columns rising from a busily-patterned marble floor. It's a dramatic entry, but it's dwarfed by the scale of the oddly-named saloon beyond where skylights 15 metres overhead brighten the carved stonework of the upstairs gallery.
Around the perimeter 20 painted heraldic shields belonging to successive generations of the Herbert family are just one indication of the history here; and so are the large oil portraits throughout the house of the earls and their families, from the first in his formal red velvet jacket and lace cravat, all the way to Geordie in a business suit and the Countess herself casually posed in trousers on the arm of a chair.
The day-trippers, however, are showing more interest in the framed photographs on the grand piano and side-tables in the drawing room: in among family skiing holiday snaps are others featuring the Queen and Duke of Edinburgh, Princess Margaret, Charles and Diana. "Oh yes, most kings and queens have stayed at Highclere," Fiona says airily, adding, "My father-in-law was one of the Queen's best friends, and she is godmother to my husband."
As a Downton Abbey enthusiast I find the rooms enjoyably familiar. It's fun to recognise the bedroom where, in the programme, Kemal Pamuk should have died, instead of along the hallway in Lady Mary's bed; or the desk where Lord Grantham sits to discuss his valet's gammy leg with the butler; or the morning room where the Dowager Countess and Lady Grantham hatch an uneasy alliance.
But there's much more to Highclere than scene-spotting. The dozen-plus rooms open to the public are opulently, even extravagantly, furnished.
In the saloon there are rare gold-embossed leather wall-coverings dating from 1680, a high marble fireplace and heraldic wyverns - two-legged dragons with a lizard's tail - on the fire surround. The large but cosy library has 6000 gold-tooled books on its shelves and some invitingly squashy armchairs.
Next door the music room is light and dainty with gold and silk embroideries, in one corner a mahogany desk and chair on carved lion's legs, used by Napoleon at St Helena. The dining room, where the table seats 24, is dominated by a huge Van Dyck painting of Charles.
In fact in every room there are smaller treasures to spot: beautiful china, clocks, tapestries, statuary, furniture and paintings collected by earlier earls on their travels.
All those souvenirs are eclipsed, however, by what's downstairs in the cellars. Before Downton Abbey, the Carnarvon name was best known for its Egyptian connection: it was the fifth earl who funded and assisted Howard Carter's investigations, culminating in the discovery of Tutankhamen's fabulous tomb in 1922.
"It was the first global media event," Fiona says. It was also the end of the earl, and the folding razor with which he nicked a mosquito bite, leading to the septicaemia that killed him, is on display in the basement.
Asked about the Curse of the Pharaohs, she says, "Carnarvon wasn't a well man, but there are some really strange coincidences. Tutankhamen's mask is made from sheets of evenly-beaten gold, but there's just one small weak spot, and it's in exactly the place where Carnarvon was bitten by his mosquito. Also, at the precise moment of his death in Cairo, all the lights went out in the city and, eerily, back home here at Highclere, his favourite terrier Susie suddenly howled and dropped dead."
I find the stone staircase behind leading down to the cellars oddly much less inviting after that, but in the arched brick tunnels where the servants used to polish the silverware and sharpen the knives, people are pressing their noses to glass cases of ancient artefacts. Most of them - faience beads, gold rings, mummy wrappings - are from earlier digs, but there's a mock-up of the entrance to the young pharaoh's tomb with peepholes to look through as Carter did when he broke a hole in the door to the burial chamber, the earl behind him. Written on the wall is Carnarvon and Carter's thrilling exchange: "Can you see anything?" "Yes, wonderful things!" That's as good a way as any to describe Highclere Castle.
CHECKLIST
Getting there: Cathay Pacific flies from Auckland to London daily. For more information or bookings. Highclere Castle is on the border of Hampshire and Berkshire near Newbury, a 90-minute drive along the M4 from London. There is no public transport to Highclere from Newbury.
Highclere Castle: Entrance to the castle includes the extensive grounds and gardens. It is open 11am-6pm from Sunday to Thursday in summer (July to September), as well as throughout Easter and on the May Bank Holiday weekend. It is occasionally closed for filming or weddings.
Downton Abbey: The first television series is being repeated on Prime on Saturday nights, and the second series will screen this month.
Further information: For more about visiting Britain, see visitbritain.co.nz.
Pamela Wade visited Highclere Castle with assistance from VisitBritain.
