If you take photographs in, say, a museum then you should seek permission of the owners or operators of the museum before publishing images. An object may itself be copyrighted and/or if you enter someone else's premises you will have agreed to terms and conditions (i.e. the fine print). If admission is free you may not have been given any conditions but it would be only polite to ask someone if permission to publish is necessary because there might be something on display which is copyrighted. Unlikely at Chatham, but there might be some items on loan.
You might also like to read some of the documents linked to here:http://www.web2rights.org.uk/documents.html