http://www.theguardian.com/lifeandstyle/2014/mar/22/free-fun-20-adventures
Here is number 5 (In Norwich - available at Eaton Park and also the new Common Room on St Benedict's Street)
5. Play ping pong
One of the best things about ping pong – the casual incarnation of the more organised table tennis – is its accessibility: anyone can play. Last summer, the Ping! initiative saw 40,000 people play ping pong in just one month in Brighton and Hove. The tables will start to reappear this month, with free coaching sessions and events in July and August. There is a trust policy with the bats and it seems to work – though Ping! replaces them if they do go missing.