The natural cave that bored straight through the soaring 1,000m high, 4km long limestone wall of the Berniere Ridge on Spain's Costa Blanca was only 20m long.
But a crouching, crawling passage through its narrow, bumpy length led me from the heights of the rugged, rural Spain I had come to visit to a bird's-eye view of the beaches and the glittering azure sea that draws millions of visitors every year.
Benidorm's ranks of tourist hotel towers were visible in the brilliant sunshine just a few kilometres away from my towering, rocky vantage point.
I had emerged from the "other Spain" - a spectacularly wild landscape of steep gorges, forbidding peaks and ridges, sweeping hillsides dotted with remote dwellings and hamlets, serried ranks of stone terraces of almond and cherry trees, vistas of valley lands of orange and lemon groves, and acres of grape vines.
The Ridge, patrolled from the air by wheeling choughs and a kestrel, and approached by a sometimes steep, twisting ascent from the blossom trees and grape vines, was the culmination of a week-long Vistas of Valencia guided walking trip with Headwater Holidays.
My aim was to explore the many delights of rural Spain - tantalisingly close to the beach culture of the coast that attracts visitors by the planeload - still so untouched by popular tourism that there remain areas where you can walk all day yet meet no one.
Once through the cave, I picnicked under a blue sky among the ruins of a 16th century Moorish fortress high on the ridge overlooking the coast (a reminder of Spain's sometimes turbulent past) as a herd of goats, bells clanking, foraged on the scree far above me.
As I returned to my circular walk's starting point, further inland, I walked past the yawning chasm of Echo Gorge, deep in which a herd of fighting bulls could be heard exercising.
My holiday base was the 17th century, traditionally decorated Casa Carrascal hotel tucked away along a narrow, colourful street in the tiny hilltop village of Parcent, overlooking the orange groves, almond trees and grape vines of the Jalon Valley, in the Marina Alta region of Valencia, just over an hour's drive from Alicante Airport.
Returning there from an early exploration of the maze of Parcent's steep streets and squares, I had to take cover in a doorway as a pelota ball whizzed by.
The street outside the hotel doubles as an occasional court for the traditional handball game, with street lighting guarded by wire cages, and players in long white trousers.
The Casa Carrascal has been owned and run for a number of years by David and Sue Eaton, from Oxford, who exchanged the long hours and stress of jobs in the UK to successfully fulfil their vision of a new life running walking holidays in Spain.
"It was a gamble, but we enjoy the quality of life which is quite special. We love the people, the mountains and being out and about," says David, who does all the cooking, with menus - including traditional paella and tapas - featuring local, fish, meat, vegetables and fruit.
The couple also guide the walks and are knowledgeable about the area's history, traditions and nature, pointing out bird life along the way, including eagles and other birds of prey, and some of the hundreds of varieties of flower and plants, which are popular with visiting botanists.
Tiny Parcent, population just 1,000, is ideally situated as a centre for walking holidays, with some routes starting from the village itself. Indeed anyone who thinks the planned day may be too challenging can be advised on easier strolls in the vicinity.
The village is surrounded by mountain ranges, and safety conscious David and Sue pick their circular treks from 32 routes they have researched, though there are nearly 70 more in the area.
One of my walks onto the spectacular Caballo Verde Ridge - high above the …