Work has begun on a £200m development in Llanelli, which is the largest ever regeneration project in south west Wales.
The Wellness and Life Science Village at Delta Lakes will create up to 2,000 jobs and boost the economy by £467m over 15 years, officials have said.
The village is a key project for the Swansea Bay City Region.
It is earmarked to receive £40m as part of the £1.3bn city deal funding.
The plans include an Institute of Life Science, with facilities for business start-up, research and development, a sports and leisure centre, a wellbeing centre and hotel, an assisted living village and an eco park.
The project is being led by Carmarthenshire council in partnership with Hywel Dda and Abertawe Bro Morgannwg health boards and Swansea University.
Council leader Emlyn Dole said it was a "very exciting time for region" and will encourage people to lead healthier lives, with care being delivered closer to people's homes.