This was an hour after Arenal startled everyone in the dining room by blowing it's top. It was several times louder than any natural sound I'd ever heard. The dining room fell silent for seconds, then the sound of chairs pushing away from tables and people scrambling for the observation deck!

Update:2025 As it turns out this was the last eruption Arenal has had in 15 years! How lucky to have been there at the right time.