The Pacaya Volcano is a must-do experience in Guatemala.  The sightseeing is truly unique, since it is not so often you get the chance to climb an active volcano!  You don't need to be an experienced hiker to do this, because you can get almost half way up the volcano by car. 

Getting to the very top of the crater takes about 2.5 hours.  The hike is not very steep, except for the crater itself, which is like a big pile of gravel.  It will get cold at the top, so bring at least a sweater and/or windbreaker.  Going up the volcano provides breath-taking views of the surroundings and the volcano itself.  Depending on the volcano's activity, you will get to see lava rivers and chunks of lava shooting out of the crater!  During high activity, a lot of people will stay overnight to better appreciate the lava sights, but this is mainly taken as a half-day excursion.

When visiting the Pacaya Volcano, try doing it with a tour operator, since it is best to go with a guide.  The Pacaya Volcano is a great source of heat, so it provides nearby town Amatitlan with thermal water springs.  A suggested combination with the Pacaya volcano is the legendary Baños Termales Santa Teresita (www.santateresita.com.gt).  This is a day spa with a unique stone arquitecture that uses thermal water from the Pacaya Volcano.  It provides all natural and organic spa treatments and thermal water circuits, which are great for soothing the body's muscles after coming down the Pacaya Volcano.  So in one day you can visit the Pacaya Volcano in the morning and head back for lunch and a thermal circuit in Santa Teresita before returning to your hotel.

Amatitlan is a town located at 30 minutes driving distance from Guatemala City or Antigua.  It is located next to the Amatitlan lake, and is famous for the typical hand-made candy called Mazapan, which is very much appreciated by the locals.  Try combining both destinations, which are located in the way of one another.  It will be a really nice trip worth your while.