We are headed to Costa Rica one week from today. We are getting in late, so we are spending the night at Adventure Inn and then heading out in our rental car around 7:30 a.m. to Arenal. My plan was to stop at the Poas Volcano on the way. Then it hit me that all of our stuff will be in the car with us, so basically that means we can't leave it unattended while we sight-see. So should we just skip Poas and anything else we might want to see on the way? Or is there someway for us both to get out of the car, leave our stuff and not get robbed?

I probably would skip it, it will take you longer than you think to get to Arenal. If you need an afternoon activity around Arenal I recommend the La Fortuna waterfall or one of the hot springs such as Baldi, after you check in.

I'm not sure I would "skip it." It only takes 3 hours or so to get to Arenal so you would have time.

As for safety of your stuff -- if you have a car with a trunk, you could put everything in the trunk. Take your important stuff with you - passport, camera, etc. It's been a while since I have been there so can't say for sure if there is a security guard. Maybe someone who has been there recently will answer.

Only go to Poas if you can get there very early. It clouds over later in the morning. It really is beautiful and I don't want you to miss it, but if you are tight on time, you may consider skipping it.

If you put your luggage in your trunk, I think everything will be okay. I write about my adventures quitting my job and moving to Costa Rica at my blog:
www.happierthanabillionaire.com

We were there last Feb. While there are no security guards per se, you do have to buy an entrance ticket, then you're also given a parking coupon where you need to pass a through another gate to park. Then an attendant tells you where to park. It's pretty secure and with the number of tourists and park personnel coming and going; the risk of a break-in I would think would be nil. If you can get all your stuff in the trunk, no problem. The whole park can be taken in a couple hours or less. We didn't do the visitor's center.