Ive done this tour before once and a night tour and loved it so I wanted to bring my kids who have never been. My daughter (10 yrs) loved it, my youngest (7) was a little bit scared he said but he was fine going round, he just held my hand. We met by a tourist info booth/ telephone box at Lawnmarket/the royal mile and took a little bit of different walk to the vaults due to the royal mile being so busy with the fringe, there was a steep road to walk down but it was fine for us. Paige our tour guide was great, came across as very friendly and was enjoyable to listen to. This one isn't a ghost tour but paranormal activities are mentioned and the setting just makes the tales more eerie compared to a walking tour outside. The underground streets and vaults are fairly spacious so you don't feel claustraphopic and are quite dark and damp in places, lit by emergency lights. I do wish the tour was a little cheaper at nearly £60 for the 3 of us for an hour but I do recommend it as a unique interesting addition to your visit to edinburgh.