Publicity ideas for Historical Forts!

I help at 2 WW2 fortresses and would welcome ideas on how to publicise them with zero budget – (ASBL status and operated and maintained exclusively by volunteers)

Forts are open to the public once a month (and other times for groups)

Have placed the open days in the events section of this site

Would welcome other suggestions and ideas that would target the “xpats” who are interested in WW2 history and want something to do at a weekend – or might be interested in a “group” visit.

Thanks