A pilot project aims to get people to ditch the car for the bus
Tourists are being urged to leave their cars behind for a bus tour of nature and wildlife highlights in Ceredigion.
All Bws Biosffer stops will be within the Dyfi Biosphere reserve, a conservation area promoting sustainability and the local economy.
Attractions include the Ynyshir RSPB reserve - the location for the BBC Springwatch programme.
The project will run twice a week until 28 August.
"Bws biosffer is part of the sustainable tourism in the Dyfi Biosphere project," said Gwawr Davalan from Ecodyfi who are behind the project.
"It offers an easy way to visit some of the area's key attractions without using your car."
The United Nations education, science and cultural organisation (Unesco) made a part of the Dyfi Valley a biosphere reserve in 1976, but rule changes in the 1990s forced sites to reapply under new criteria.
The Dyfi biosphere is a conservation area promoting sustainability and the local economy. It covers areas including Aberystwyth and Machynlleth.
Apart from Ynyshir other attractions include the Dyfi Osprey Project, and Ynyslas visitor centre and sand dunes.
The bus matches up with train timetables and is designed for wheelchairs and children's buggies.
Richard Jones, from Machynlleth-based Lloyds Coaches, said: "It's an opportunity for local people, and for people who visit, to learn more about the area.
"It's a way to showcase what is here and from the point of view of the company it also helps to safeguard jobs.
"Before it started we held a session with the drivers and the biosphere people so that they could explain exactly what it is, so the drivers can answer any questions customers have," he added.