I think it would be cool to investigate some ruins.
Saijaku Muhai no Bahamut has a couple of them. Strange structures filled with pillars, moss, and secrets yet found. The trade-off, of course, is a lot of danger. Creatures may be protecting the place. Latent, unknown devices may be itching to go off after lying dormant for hundreds of years. So long as I could avoid all of the risk and reap all of the rewards, I would try to trek through one.
Sadly, for Bahamut, it does not just have ruins. It’s in ruins, too.