One of the best things about living in Liverpool is that green spaces are readily and cheaply accessible by public transport. For the princely sum of £2.10 return (with Railcard discount), I was able to jump on the train to Hoylake and spend the afternoon in Red Rocks Marsh Nature Reserve. I was almost put off by the freezing weather in the morning, but by the time I got there at about 1pm the sun was out and it was quite pleasant, although the unmelted ice was crunching under my feet as I walked along the beach.
I found out about this thanks to Merseytravel who put out several leaflets about exploring the Merseyside area by public transport. This one is called Walk&CycleAbout Wirral Peninsula and can be downloaded from the web site. Alternatively get a printed copy from any Merseyrail station or Merseytravel shop.
On the cards for when the weather warms up is the Wirral Country Park. Last time I attempted to walk the whole length of this path, I got lost in the amusingly-named village of Gayton and had to abandon the trip.