North and East London are only just over an hour away, Cambridge is half an hour away. The closest train station is Great Chesterford (on the London liverpool street to Cambridge line) and takes 15 minutes in a car/taxi. Audley End is the next closest railway station and then Cambridge.
We do recommend using our Facebook event group to try and find taxi shares, an 8 seater taxi will cost £49 from central Cambridge and a 4 seater taxi will cost £39, some taxis from and to London cost as little as £100. It is not safe to walk to the site from any direction as the A1307 is a very busy road.
Shuttle buses run from Cambridge station and possibly from Audley End if there is a demand.