The group comprises estate papers relating to the administration of the Garn estates, mainly in the parishes of Denbigh, Henllan, Llanefydd, Llanrwst, Nantglyn and St Asaph in Denbighshire, Rhuddlan, Flintshire, and Caerhun, Caernarfonshire. They include rentals, 1658-1784, and other estate management papers, 1708-1912, title deeds, 1572-1903, maps and plans, 1776-1866, and domestic management papers, 1725-1885.

Deeds, documents and probate records, 1617-1853, relating mainly to the parishes of Caerhun, Conwy, Dwygyfylchi, Gyffin, Llanbedrycennin and Llannor, Caernarfonshire, and to the Abbey estate, in Denbighshire, Merionethshire and Caernarfonshire, 1811-1819; notes on sermons, 1861-1889; and miscellaneous papers relating to Amlwch, Anglesey, 1801-1868.