General

Castles on the Web.com
Castles on the Web offers an extensive database of all things Castle related including a castle photo gallery, free castle web pages, hundreds of castle links, castle site of the day, castles for kids and more.

SITE O
SITE O is an international research/discussion group of people from around the world. All the members have an interest in fortifications and/or artillery. The membership includes authors, members of the military, museum curators and professors who are involved in research on these topics

Park Net - National Park Service
ParkNet is the official gateway to the sites and services of America's National Park Service.

Coastal Fortification on the Gulf of Mexico
This website contains historic information about coastal fortifications in the United States.

North American Fortfications
This website contains information about historic military forts in the United States and Canada.

Civil War Field Fortifications Website
American Civil War field fortifications digital research library.

Associations

The Coast Defense Study Group
The Coast Defense Study Group (CDSG) is a non-profit corporation formed to promote the study of primarily American seacoast defenses and fortifications.

Hadrian's Wall

Hadrian's Wall World Heritage Site
This website contains historic and tourist information about Hadrian's wall.

The National Trust - Hadrian’s Wall & Housesteads Fort
Housesteads Fort is one of the best-preserved of the thirteen permanent bases along the Wall. The fort is owned by the National Trust, and maintained and managed by English Heritage.

Corregidor

Corregidor Historic Society
Online publication of the Corregidor Historic Society.

U-boat

uboat.net
This is the most comprehensive U-boat site on the net, and includes articles, forums and a gallery.

The U-Boat bases
U-boat bases of the second world war in France. Includes photos, maps, descriptions and a history for each base.

Links policy