Pontin's said it saw an increase in 2009 holiday bookings
Visitor accommodation is to be doubled at the Pontin's holiday camp at Prestatyn in Denbighshire.
Owners Ocean Parcs said the capacity of the Prestatyn Sands Park will reach 5,000 visitors over three years.
It said the £15m expansion will add 300 jobs and bring 200 construction jobs. It also plans to expand the complex to 7,500 visitors in subsequent years.
A spa, bingo, betting and gaming facility, refurbished nightclub and bigger swimming pool are all planned.
Ocean Parcs bought Pontin's, which is famous for its Bluecoats entertainers, in March 2008.
It operates six centres in the UK, although it has announced the closure of its Blackpool site with the loss of 70 jobs.
A spokesman for the company said basic refurbishment has already started at the Prestatyn site and work was to begin next year on improving the facilities.
A planning application for the expansion was also expected to be submitted next year.
The company announced earlier this year it was investing £50m on developing its holiday camps.
Chief executive Ian Smith said it had not been an easy decision to close its Blackpool park but the aim was to make Prestatyn Sands the firm's biggest location.
He said: "It's a cracking site in a cracking location and we have confidence in the team there and in north Wales as a tourism location.
"It's close to some of the main conurbations and it's easy to get to."