Went this week to the Lee Valley Regional Park for our walk. The map we printed off said "moderate to challenging". So off we went. First, a pond so covered in algae that it looked like mottled glass and was just begging me to try walking on it, but I resisted. On then, past many fields planted with over-wintering root vegetables: turnips - or possibly swedes (that's rutabagas to my USA contingent), all on completely level ground. To our left, a high, wire fence on the other side of which was the old Royal Gunpowder Mills, though from where we were there was nothing to see aside from woods, a creek and occasional overgrown fields.

After a time we came to clearer water, which is part of the old river Lee (or, confusingly, Lea) and met a number of birds, including, though we didn't know it at the time, a bittern (sorry, no pic). Bitterns are one of the most threatened bird species in the UK, mostly due to their ever-decreasing habitat – they like reeds along water edges – so we count ourselves lucky to have seen it. Soon after we also found ourselves on a paved path and passing or meeting quite a number of other people out for walks. It was all getting a little too populated for us and so, along with the fact that our parking lot closed at a particular time, we decided to go cross country, losing out the top half of the walk and getting away from the over-groomed 'country park' feel near the water.

We passed a farm I remember from when my son was small – the sort of 'working' farm that is open to visitors all year round, so city kids can see cows being milked and baby lambs up close – and carried on until we came out on to a road. Although our walking map helpfully had an exclamation mark on it at this point and, in the key, said "be very careful of traffic on this stretch", it was still alarming to find ourselves on a twisty bit of road with cars going very fast indeed and no pavement or verge at all to walk on. We asked ourselves repeatedly if we could possibly be following instructions correctly because it really did seem far too dangerous to walk along but, being the sort of people who feel they have to finish once they've started, we carried on and eventually found the next waymarker and escaped on a small path that led away and up from the road.

The operative word here is up. By the time we made it to the top, I was ready for a little rest! Too bad the wood we had arrived in was a bit muddy for sitting down in, but at least now I understood why the walk had been described as "moderate to challenging"!

We eventually came out on a high point from where we could just see in the distance the city of London, though behind us it felt and looked like country. It is one of the remarkable things about this little island: that you can be surrounded by concrete, crowds, noise and cars, but be away from it all in a very short time indeed.