San Ignacio is a small town in the Cayo region of Belize. San Ignacio, or Cayo as it is often called locally, is on the Macal river, and makes a good and affordable base for exploration of the stunning regions around it, with plenty of day trips to be taken and several decent tour guides willing to take you. It's also an important transit town en route to or from Guatemala. Cayo is known for having a multitude of ruins, caves, and rivers, all of which can be explored by travellers.
If you are looking for some place to sleep there are a hand full of full service resorts, but the real beauty is in the lodges. They come in all shapes and sizes, and they are always unique. In the San Ignacio proper, you can find some good hotels, but make sure that if you are looking for something quiet you aren't too close to Burns Ave.