Are there opportunities for 55 year olds to teach as well?

There are lots of jobs for those in their 40s, 50, 60's and some in their 70's but it depends on which country you teach.

I am 65 years old and some ability with Spanish. I wish to become certified to live and work in Costa Rica. Is this something that is worth pursuing? What is best recommendation to prepare and become certified and best qualified.