Centre for Alternative Technology

CAT was founded by businessman-turned-environmentalist Gerard Morgan-Grenville, and opened in 1973 in the disused Llwyngwern slate quarry near Machynlleth (once served by the narrow-gauge Corris Railway), where it occupies a seven-acre (28,000 m²) site. The organisation was originally known as the "National Centre for Alternative Technology". David Lea and Pat Borer won the Gold Medal for Architecture at the National Eisteddfod of Wales of 2001 for their work on the AtEIC building at the CAT, and an RIBA Regional Award for the WISE building in 2011.

Originally opening in 1975, CAT’s visitor centre is open to pre-booked group visits and is full of interactive displays and working examples of renewable energy, green building, organic gardens, biodiversity and more. Schools, universities, community groups, businesses and more come to CAT to learn about these topic areas. It is a registered charity. The facilities and exhibits include: In 2023, the CAT announced that financial pressures had forced it to stop admitting walk-up day visitors, although it would continue to hold group visits and other events and courses.