Guanacaste is in the northwest of Costa Rica on the Pacific coast. Journey down the Corobici River and continue on to the Tenorio River. You will come across hot springs, sulfuric ponds and geysers. Visit the Rincón de la Vieja Volcano National Park, which is home to approximately 357 species of birds, several waterfalls, a small lake, and contains what is probably the largest concentration of purple orchids in the world.