The new BBC Wales drama studios in Cardiff Bay are being officially opened by First Minister Carwyn Jones.
Roath Lock provides a permanent home to three flagship dramas - Doctor Who, Casualty and Pobol y Cwm.
The studios form the BBC's largest drama production centre in the UK, part of the Porth Teigr project in Cardiff's former docklands.
It was built following the BBC's commitment in 2008 to double its television network production in Wales.
Around 1,000 visitors took a rare peek behind the scenes of the 170,000 sq ft (15,800 sq m) site, which is equivalent to the size of three football pitches, at the weekend.
The open days included the TV sets of Casualty and Welsh language soap opera Pobol y Cwm and a chance to see props used in Upstairs Downstairs and Doctor Who.
Tickets for the visits on Saturday and Sunday were given out on a lottery-style basis and the application for them was oversubscribed.
Speaking ahead of the official opening, the first minister said: "This studio complex is a major step forward for the creative industries in Wales and will be home to famous drama productions that are viewed across the world.
"The creative industries, from TV, film and theatre are of major importance to our economy, supporting jobs and investment and the Welsh government is determined for this to continue.
"BBC Cymru Wales' Roath Lock is a symbol of what Wales can achieve and the bright future we have ahead of us."
The long-running medical drama Casualty is now made in Cardiff The complex is the first industrial building in the UK to be given a Breeam outstanding certificate for its green credentials, the highest possible environmental rating.
The name Roath Lock was chosen following consultation with BBC Wales staff.
The lock refers to the waterway linking Roath Basin to Roath Dock and the bay, and the studios are built next to the former lock-keeper's cottage.
The drama village is the focal point of the Porth Teigr project, which the Welsh government has said will host up to 8,000 jobs when completed.
As well as shops and restaurants, the finished project will include 1,000 homes.
BBC Director-General Mark Thompson said: "The BBC is committed to Welsh broadcasting and to content from Wales.
"We're tapping into the great talent, the great creative ideas and the great tradition of storytelling that already exist here in Wales and we're exploring new talent, new possibilities and new opportunities."
Director of BBC Cymru Wales, Rhodri Talfan Davies, added: "We know our audiences in Wales are very proud of BBC Wales' drama success - and this opening weekend of events has been a chance to say 'thank you' for all their support.
"Roath Lock is already the BBC's largest drama production centre in the UK and we're proud of our track record in producing world-class programmes.
"But the real excitement is about what lies ahead - I have a real sense that the creative possibilities here are limitless".