BRISTOL became the first place in the UK to ban traffic from the city centre.
Mayor George Ferguson described yesterday's event as a great success.
Traffic was kept off seven roads, including Park Street and Baldwin Street, for the first of his Make Sundays Special events. Mr Ferguson was inspired to stage the one-day festival after hearing of the success of similar events in other European cities, including Bristol's twin-city Bordeaux.
Despite weather more typical of October than summer, thousands of people young and old filled the streets under gloomy skies and in a chilly wind to support the inaugural event.
Sixty-six-year-old Mr Ferguson hailed it a huge success, and one which further elevated the city's status.
He said: "The feedback has been incredibly positive, not just about the event but about what's happening in Bristol – the fact that it's on the map and getting lots of attention.
"People are feeling really good about Bristol and the kids are happy."
The event saw Park Street become a playground, with families sitting on bales of straw and children drawing with coloured chalk on the road.
College Green was devoted to solar power demonstrations and exhibits, days after Bristol's bid to be the UK's first solar city was launched.
Streets in the Old City, including Baldwin Street and Corn Street, were lined with food stalls offering locally- produced treats as street entertainers including stilt walkers, jugglers, dancers and musicians kept the crowds amused.
Baldwin Street played host to a basketball court, Cascade Steps became a music stage showcasing local acts while part of the Centre was taken over by a BMX demonstration arena, which visitors flocked around to catch a glimpse of the bikers' daring tricks.
Families on bikes rode around a special signposted cycle circuit which took in Castle Park, Queen Square and Temple Meads.
Elsewhere, in Millennium Square there was an Electric Vehicle Show and in College Green families queued to go inside the popular Colourscape tent, which promised visitors a unique experience of colour and music.
The event fell on the final day of Big Green Week and will be repeated once a month for the next five months.
Mr Ferguson, who has traded his trademark red trousers for a green pair after Bristol was crowned European Green Capital 2015 last week, said the event had drawn people from far afield and would provide a boost to the city's economy.
He said: "I was amazed by the number of people not from Bristol that came.
"It's great for the economy. I want people here spending Welsh pounds and Birmingham pounds as well as Bristol Pounds.
"I don't know how many people came but it's thousands. On a grey day when people would have probably stayed at home or done something inside, they came outside.
"I want to congratulate all the people who have helped organise it.
"It's easy for me to have an idea but it's a lot of work to turn something from an idea into a reality.
"I want to praise the officers and others that made it happen.
"Once something like this is done once, it's easier for us to roll it out again in the future.
"I'm looking forward to getting the feedback to see what people think about it. I'm sure it's good for Bristol's position in the country and is a really good build up to us being European Green Capital in 2015."
Among those at the event were Samantha Griffiths, 47, from Southville, her husband David, 51, and their daughter Isobel, four.
Mrs Griffiths said: "We heard the streets were going to be closed and we thought we would see what was going on.We knew there would be stuff for the kids.
"I like to support these types of initiatives and think it's a good idea."
Elodie Hicks, 34, from St Andrew's, was at the event with her mother Jane Day, and children Eartha Wilde, seven, and Monty Wilde, three.
Ms Hicks said: "We came because it's a green event and one of my friends was involved in it running a solar stall.
"Having seen this, I would like our road to be closed off to traffic for this type of event. The more free things the better really, and it brings the community together."
Roger Hornby, 40, from Westbury- on-Trym, and his family stumbled upon the event after visiting the City Museum & Art Gallery in Queens Road.
Mr Hornby, who was with his wife Helen, 38, and children Wilbur, nine, and Edward, six, said: "Bristol is very good at this kind of thing.
"These events are good for building a sense of community and create a nice feeling in the city."
Living Heart Bristol, said that one in three people it questioned during the event wanted to see some of the closed roads shut on a permanent basis..
The group said 70 more people joined its supporters list, pressing for the council and the mayor to make a permanent change.
Making Sundays Special followed a big market held in the Old City on Saturday.
There were more than 200 stalls in Corn Street and surrounding streets selling artisan food, vintage curios and arts and crafts.
A day earlier on College Green, Mr Ferguson launched Bristol Solar City, a project aimed at establishing the city as the UK's solar capital.
Mr Ferguson said: "I want to make Bristol the UK capital for renewables, ensuring we become less dependent on external sources for our energy.
"Solar panels on Bristol City Council's own buildings, together with other public buildings across the city, will make a significant contribution towards Solar City's ambitious target over the next few years."
More Making Sunday Special events are planned for Sunday July 21, Sunday August 18, Sunday September 29 and Sunday October 20.
Roads affected will be closed from 9am to 6pm on each of these days.