Naha, Okinawa former Japanese Navy's Headquarters

I'm interested in visiting this site, but have a question about the steps. I realize there are 100 steps to get into the tunnel, but am wondering if that's 100 steps down and 100 steps back up? Is there an alternate to taking the steps up, like a ramp? I'm somewhat fit, but I don't know if I'm able to push it that far. ;p

Sorry, I have not visited the site, but here are a couple of videos. Looks like down when you enter and then up back up with no ramps. However, it looks like you can take your time to rest on your way up. After watching the videos it looks like an interesting site to visit.

Yes, it's a one way path. The steps are down (and they're large, relatively low steps) and the exit is via a long ramp. It's all done at your own pace and there's enough room to pass/stop if it came to it.

Note: if you walk to the tunnels, you may encounter at least that many steps as the entrance is near the top of the hill. Depends which way you come.

Thank you both for the valuable information. After reading your posts and watching the videos, I'm totally up for this!