Take the tube out to Hammersmith for a river walk. From the tube station, there is only a short walk down to the river. Stroll along the Thames and watch the life by the river. There are many pubs in London and along the riverwalk, you find a whole bunch of them. Why not try out the Dove, well situated on the path as you walk along the river. In the summer have an open-air terrace and in wintertime, you find an open fireplace in the pub.
Check out the Hammersmith River Walk in the Walkster London app for walking in this area.