So when she saw a brochure advertising a 12-day break on a ranch in Arizona, her mind was made up. The retired couple from Margate joined 13 others for a holiday in the saddle, visiting film sets, swaggering through the swing doors of saloon bars, and generally acting like the Lone Ranger. "It was fantastic. We'd already been on quite a few adventure holidays, so we were used to doing something different," said Mrs Gunn.
The Gunns are typical of the get-up-and-go holiday style of the over- 50s. Travel companies have been quick to cotton on to the fact that nothing is off-limits for the adventurous, mature tourist. Trekking in the Himalayas, husky sledging in the Arctic, hot-air ballooning over the game parks of Tanzania, canoe trips in Borneo, spotting condors in Chile - the demand is insatiable.
You have to have the money to do this kind of thing, of course. But that's exactly what the grey market - as it is unkindly referred to by the industry - has. Affluent older travellers are prepared to push the boat out to get what they want.
According to a Saga survey, over-50s account for 80 per cent of the UK's private wealth, and 60 per cent of personal savings. They spend pounds 215bn a year and are major consumers of leisure and financial services. Two- thirds of today's over-50s feel at least 10 years younger than their actual age and are seeking more action-based activities.
Naturally, when you get beyond the half-century mark, the appeal of the candle-lit dinner tends to pall. Which is not to say that romance is dead. The romantic getaway is still a winner; it's just that couples won't be looking quite so longingly into each other's eyes and will need something else interesting to occupy them.
"Not only do older people have wider horizons and want to see far-flung places," said Derek Moore, director of Explore Worldwide, "they are also fitter and want to go on more demanding holidays. This means you frequently get young and old mixing together and learning from each other. It all adds to the interest, which is what people want. The only difference is that while older people are prepared to rough it with rucksacks during the days, in the evenings they want their creature comforts. It is adventure, but within safe limits."
The city break to mainland Europe - romantic or otherwise - is probably the most popular choice for older couples who just want to have a few days to themselves. Cheap flights from budget airlines, booked on the internet, have put hundreds of fascinating destinations within easy reach on any day of the week. With more and more airlines using regional UK airports, this phenomenon is now experiencing exponential growth.
Once there, having shelled out little on fares, they have more to spend on food, drink and entertainment. For my 50th birthday, my partner and I paid a total of pounds 19.98 to fly to Bilbao for a long weekend, stayed in a swish hotel overlooking the river Nervion, and proceeded to spend three days feasting our eyes on the Guggenheim museum and our bellies on Rioja and exquisite Basque cuisine.
The vast amount of expendable wealth owned by "third agers" has also given rise to what is known as celebratory travel. This could be birthday treats - such as the Gunns opted for - of second or third time around weddings, honeymoons, and anniversaries, for which couples are prepared to splash out. Often a family will link up with a group of friends to form a large party to celebrate a special occasion together.
One other factor, however, may be contributing to the growth in the senior travel market. Many are becoming convinced that, as they can't take their wealth with them, they're better-off spending it. "Once they've paid for college education and helped their children get on the housing ladder, they think they've done their bit," said David Metz, the author of Older richer fitter. "Older people used to believe in leaving a bequest for their children. Not any more."
GIVE ME THE FACTS
Saga (0800 096 0089; www.saga.co.uk)
Explore Worldwide (0870 333 4001; www.exploreworldwide. com)
Kuoni (0870 990 9905; www.kuoni.co.uk)
Older richer fitter by David Metz and Michael Underwood, Age Concern Books (pounds 16.99)