What Would You Recommend? - The Lost Symbol

This is a question I get asked all the time working in the bookstore: "What would you recommend for somebody who loved "_________"? (fill in the blank)" Usually I can come up with something, but that something can be a bit of a wild guess if it's not a book or genre I normally read. This is where you helpful people come in. If you have a suggestion, I'd love to hear it.

This is a regular new feature that I hope to post every Thursday or Friday.

For the initial week, I'm going to go with Dan Brown's The Lost Symbol. A lot of people have read it (although I am one of the minority that hasn't), and I think it's a safe assumption that if you've read this book, you've also read The Da Vinci Code (Amazon.com link).

So, if you were being asked "What would you recommend for somebody who loved this book?" what would you suggest?

I've been suggesting the Steve Berry books such as The Venetian Betrayal, because they seem to run on a similar premise of some aspect of history becoming a mystery to be solved today. To be honest though, I'm just running on the jacket blurbs for this because I haven't read any of them yet (bad of me, I know, to suggest books I don't know anything about), although I do have this one on my TBR list. This just isn't my normal reading fare, so if anyone does have some other suggestions I'd love to read them. It's your turn now.