Maesgeirchen is a large housing estate on the edge of the city of Bangor in Gwynedd, north-west Wales, with roughly 4,000 inhabitants. It was originally constructed in the late 1930s, with more homes being added after World War II and in recent years. In 2003, the local council-owned pre-war homes on the estate underwent an expansive home-improvement scheme funded by the council, which saw them all fitted with double-glazing and central heating, as well as maintenance and modernisation work to both the interior and exterior of the buildings. It is the third largest single housing estate in Wales behind Gurnos, Merthyr Tydfil, the second largest and Caia Park in Wrexham, which is the largest with nearly 12,000 inhabitants.