We are used to the paperback handbooks to sites in the care of CADW, English Heritage and Historic Scotland. In the 1930s the Ministry of Works commissioned a series of Illustrated Regional Guides to Ancient Monuments in the Care of the Ministry of Works.
The series consisted of (with prices):
1. Northern England. 4/6.
2. Southern England. 6/0.
3. East Anglia and the Midlands. 5/0.
4. South Wales. 5/0.
5. North Wales. 4/6.
6. Scotland. 7/6.
I have a hardback copy of the 3rd edition for Guide no. 4 ‘South Wales and Monmouthshire’ (HMSO  1954, 3rd impression with amendments, 1959; 5 shillings) by Sir Cyril Fox, Director of the National Museum of Wales. It contains maps and black and white photographs.
The notes to the 2nd and 3rd editions observe the growing number of sites that had moved into the care of the Ministry of Works: 12 between 1938 and January 1949; and a further 8 between 1949 and January 1954.
Chronological Table, 10-11
The Geographical Background, 13-14
Prehistoric Periods, 15-21
Roman Period, 22-25
Post-Roman Periods, 26-55
Notes, 56-57 [Gazeteer of 49 sites, 58-68]