I would definitely mention them! You don't have to make a separate entry for each open day - you can group all of them under one entry. All experience is good experience in this case. The firms are likely to appreciate your commitment to getting more exposure and learning about different types of firms and practice areas!bit of a silly question, but should you be mentioning open days in your 'work experience' section? especially ones where there was no real application/competition?
i've stuck to not mentioning them in my previous cycles and although I did manage to get past initial apps, I was wondering if not mentioning them has stopped me from progressing in other firms.