Welcome to Wales - Where to Visit, Historic Sites and where to stay in Wales - http://www.croeso.com/
The Wales 2000 Network - Frames version of the above - good for Castles and historic Sites - http://www.wales2000.net/
Cadw - Welsh Historic Monuments
Official Wales Tourist Board Web Site - Welsh regions, culture and history. Activities and events and accommodation - http://www.tourism.wales.gov.uk/
North Wales Index - The most complete web directory covering the North Wales area - http://www.northwalesindex.co.uk
The Royal Commission on the Ancient and Historical Monuments of Wales - based in Aberystwyth.
Window On Wales - Virtual Tours from South Wales. -
http://www.windowonwales.co.uk/South Wales Information - Everything you need to know about South Wales. - http://www.south-wales.info/