Blackpool lit up when DJ Chris Evans flicked the switch for its famous illuminations on Friday night.
The illuminations run for 66 nights until 6 November
Lights are stretching beyond the promenade for the first time in 126 years with a "festival of light".
The switch-on, adjacent to Coral Island, was broadcast live on Radio 2 - the station which will host Evans' new Saturday radio show.
Chart stars McFly, Rachel Stevens, Lee Ryan and Erasure performed live in an hour long show before the switch on.
Last year Blackpool celebrated the 125th anniversary of the free show. This year's illuminations mark the 125th anniversary of the invention of the light bulb by Thomas Edison.
An exhibition celebrating this, and the illuminations, is running at the Solaris centre in Blackpool.
The illuminations shine non-stop for 66 nights
Cable and wiring stretches more than 200 miles
The amount of electricity consumed costs about £50,000
Illuminations which have gone missing over the years include an Egyptian mummy and Lego men
The switch-on is always live when the button is pressed
A worker for Colonel Gadaffi tried to buy up all the illuminations
Famous "switchers" include Jayne Mansfield, Kermit the frog, Red Rum and Terry Wogan
This year's display includes the "They Shoot Horses Don't They?" artwork, which is a huge glitterball on the promenade, with 45,000 mirrored squares.
An Indian-made peacock featuring 135,000 coloured light bulbs - entitled Bajra - goes on display at the Winter Gardens from October.
Director of the Festival of Light, Philip Oakley, said: "Blackpool Illuminations are testament to the early pioneers of electricity and lighting.
"Their existence is a result of the ingenuity, ambition and creativity of people over one and a quarter centuries ago.
"The Festival of Light is about those same desires which push technological and creative boundaries forward."