In Paris, Notre Dame still dons the tourist maps, despite a horrific fire that ripped through the iconic cathedral in 2019 and the painstaking restoration works underway ever since.

The hilltop citadel of Athens, the Acropolis, has been attracting visitors long after the gods for whom the temples honour were superseded by Christianity.

The list goes on: Cambodia's Angkor Wat, the White Temple of Chiang Rai, the Tian Tan Buddha in Hong Kong, or Malaysia's Batu Cave complex.

All deeply religious and heavily-touristed. All are at or near the top of their city's or country's most-visited site.

And, while there remains sites like Mecca, where only Muslims can visit, it's always intriguing to me when I see that many of these still-functioning religious sites - and entire states like Vatican City - attract enduring crowds of irreligious, agnostic, even atheist visitors.

And this remains true even as the percentage of devout followers of organised religion ebbs lower.

I must have clocked up many dozens, if not hundreds of these sites from Brazil, to Egypt, to Vietnam to Turkey to Hong Kong, Russia and Mexico (and all without conversion).

On the backpacker trail of southeast Asia it's not uncommon to become "templed out" such is the frequency of a Buddhist temple visit to punctuate the tropical budget-friendly itinerary.

The non-religious pilgrimage to historical sites has been witnessed nearly as long as mass tourism has been going on, and simply repackaged as "heritage tourism".

Researchers at Ulster University Business School back in 2003 (long before selfie sticks and mass social media) found "many people travel to sacred sites not only for religious or spiritual purposes but do so due to the way they are marketed, i.e. as a heritage or cultural attraction to be consumed".

Does a superficial yet peaceful visit and a couple of contemplative photos give credence to the idea that your four-week trip dossing about in the sunshine was actually a pilgrimage of sorts, under that conveniently vague terms "spirituality" or "wellness" in which you can dabble without committing?

My own collection of photos seems to attest to that. Read more

• Josh Martin is a London-based journalist who writes across business and travel topics

I've always felt just the tiniest bit uncomfortable when touring religious sites - churches, temples, synagogues and the like - knowing I'm not a believer.

It gives those visits an air of voyeurism, that I'm peering in at something I'll never be part of, and maybe it's not welcome.

For all atheistic travellers, that must be something of a problem.

But still, there's huge value in visiting these sites.

Have a look at the 10 sites that inspire unbelievers