Regent's Park, Regent's Park, Primrose Hill, NW1 4NR
A day of live music, performance, exhibitions and workshops to encourage people to take steps towards a greeener lifestyle.
There'll be hands-on fashion for the eco-style conscious, a green fair marketplace, delicious sustainable food and a bikefest where you can try out a new type of bike or get yours serviced for free. Apparently you can also travel back in time, grow your own hat, milk a cow and much much more.