The Saltholme centre opened to the public in January
A multi-million pound Teesside wildlife centre has gained a "gold award" for sustainable tourism.
The £7m Saltholme Wild Bird Discovery Centre, near Middlesbrough, has received a Green Tourism Business Scheme certificate.
The 1,000-acre (440-hectare) reserve's visitor centre was designed to include a host of features which promote sustainable energy.
More than 50,000 people have visited the site since it opened in January.
The centre's walls are rammed with soil which acts as a storage heater and the building relies on the circulation of natural air, instead of air-conditioning.
Rainwater is also collected and used to flush the toilets, and the site has its own natural sewage treatment works that purifies water through a specially designed reed-bed.