Mensa Cymru is the regional group of British Mensa for Wales.
('Cymru' is Welsh for 'Wales'. It is pronounced 'Cum-ree'.)
Mensa Cymru isn't a particularly active region, quite possibly because of the poor transport infrastructure. The main concentration of members can be found in South Wales. The most active area is Cardiff who hold a well attended regular monthly meeting. Swansea also have regular activities and meetings.
The Portmeirion Weekend is a very well attended event held in the italianate village of Portmeirion in Gwynedd in North Wales but has no direct connection with the Welsh Region.
Cymrig is a SIG celebrating all things Welsh but this too has no direct connection with the Welsh Region.