Gwynedd Archives Service - Includes Gwynedd Archives' On-line Catalogue service. Currently (2018), 12,000 pages from their catalogues have been loaded into the online database. Additionally, 2,000 images have been added to the on-line collection. There is also a growing section relating to their Collections. Caernarfon Record Office, Gwynedd Archive Service, Gwynedd Council, Caernarfon, LL55 1SH. Tel.: 01286 679095, Email: archifau[at]gwynedd.llyw[dot]cymru
Conwy County Archives
The Old Board School, Lloyd Street, Llandudno, LL30 2YG Tel.: 01492 577550
Mostyn Street, Llandudno, Gwynedd LL30 2RS, Tel.: 01492 574020
Station Road, Deganwy, LL31 9EX, Tel.: 01492 584705; Email: llyfr.lib.deganwy[at]conwy.gov[dot]uk
Caernarfonshire County Library Papers and Miscellanea 1883-1973 - details of extant records on Archives Network Wales
The National Library of Wales
The National Archives has details of many archive repositories in the UK with links to their web sites, if any.