Advice for RN interested in long-term care

After much soul-searching, I have decided that long-term care may be more suited to my abilities and interests than acute care.
Need advice regarding what training or cerifications would make me more marketable in this area.
As a graduate from a diploma program, I have been a nurse since 1977. Have worked in long-term care for short intervals, but in the past had never really been interested in pursuing this alternative.
Thank you in advance for any information that would help.