It is really cool to walk near the base of an active volcano.  And, if it is clear you can actually see the lava.  Unfortunately for me it was overcast the whole time we were there. But, still a cool area and you can hit the hotsprings while you are there!

Arenal Volcano National Park is one of the most exciting places I have ever seen.  Now, I have been accused of being a rock geek, and my photo albums and souvenirs will support this assertion.  We had a room for three nights at the Arenal Observatory Lodge, which is the closest lodging to the volcano.  The very night we arrived the lava flow moved to our side of the volcano, so we spent the entire night sitting on the porch or in the rockers at the picture window of our room watching the lava flash and flow.  On little or no sleep, we woke the next morning to hike the park.  The animals, vegetation and lush surroundings were awesome in the true sense of the word.  We saw monkeys, sloths, toucans, frogs, snakes, vultures, and more.  Everything was flowering.  Definitely a place to return to, and we seldom visit the same place twice!

Do go on the jungle tour everyone offers in Fortuna, you'll end up at night in the hotsprings faving Arenal and it's the best time to enjoy the glow atop the volcano. Fortuna is where you'll probably want to stay since it's the closest village, or you'll have to stay in a kind of overpriced resort (where the hotsprings are ad you'll be there anyway if you just go on the day tour). You also get to see the guide feed and play with an alligator, but well.. its part of the show.. Good overall place to rest your bones if you've been crossing lake Nicaragua from Ometepe

Arenal is a great place to get above sea level if it's to hot on the coast. When I was at Arenal it was overcast most of the time so I only saw the volcano for a few minutes. I did some hiking from the Arenal Observatory Lodge and was impressed by the constant rumble of Arenal it always keep you on your toes, there were a few nice waterfalls also. I stayed at the Baldi Hot Springs which is a nice treat if your in need of nice hotel for a special ocasion.

Arenal Volcano National Park is a great place to visit! The views of the Volcano are amazing, especially if you are fortunate enough to see the volcano erupt after dark.
The waterfall, "La Fortuna", is also a sight worth seeing. If you like nature, this is a place you must visit at least once in your lifetime!