WE'VE got a challenge for you this week: a series of old photographs of North Yorkshire towns and villages in years gone by which we haven't named. Your task, if you choose to accept it, is to identify where they were taken - and also, if you can, when.

We'll give you the answers next week. There's no prize, sadly, other than the satisfaction to be gained from knowing you got it right. And, of course, the satisfaction of looking at the photos and taking a trip back in time around some lovely Yorkshire places in the process...

The photographs were supplied to us by Ivan Martin, the former secretary of YAYAS, the Yorkshire Architectural and York Archaeological Society. Some are from YAYAS' extensive collection of photos; some are from Ivan's own collection.

Ivan often gives talks about local history, illustrated by old photos, to history groups, church groups, WIs and 'anyone who is interested'.

A lifelong keen rambler - though he admits the best of his rambling days are behind him - he also gave a talk to the York HF Rambling Club, of which he is secretary. The Ramblers' talk was actually more of a 'when and where' quiz, featuring photos of Yorkshire towns and beauty spots that walkers might have visited themselves.

But of course, these were photographs taken many years ago. "That makes them slightly different!" Ivan says.

Members of his audience were asked first to try to identify the various photographs and to guess when they might have been taken. Ivan then gave the answers later. Our photos today all come from that quiz.

The photographs all show well-known North Yorkshire towns or locations. Some should be quite easy to guess - others perhaps less so. There are clues in most of them, though, to help you along.

We'll bring you the answers next week. But here's a little more information about each photograph, to help you get started...

1. There's at least a date on this photograph - which is actually a reproduction of an old postcard. But we've cunningly cut off the name of the place pictured. It's a well-known North Yorkshire market town. The buildings in the background may help you - though of course, we can't guarantee that they haven't changed in the last hundred years. There's a bonus point for anyone who can identify the uniforms of the soldiers on parade (well, there isn't, because there's no prize for this quiz: but you know what we mean...)

2. This is a beautiful river scene - but which river, and which town? The buildings top right might give you a clue

3. Another well-known North Yorkshire market town, which is actually not a million miles away from the town in photo 1...

4. The beck in its deep gorge running through the heart of the green in this this lovely North Yorkshire village is a bit of a giveaway. Today, you can often spot sheep grazing there...

5. This steep, narrow street should be recognisable to anyone familiar with the North Yorkshire town where this was photograph taken...

6. The Yorkshire coast, and a very distinctive slipway down to the sea that will be a dead giveaway for anyone familiar with this part of the world...

7. The Yorkshire coast again - and yes, we know it is far too easy. Great photo, though...