We flew from Houston to Costa Rica, spent one night in San Jose, and flew to Lima to spend Christmas with Family. Four days later, we returned to Costa Rica for our brief vacation in Arenal Kioro. The Costa Rican authorities asked us for our "yellow fever certificate." My husband David and I looked at each other and asked "What certificate? For what? Apparently, Costa Rica requires a certificate of yellow fever vaccination to enter, if you have stopped in Peru, Ecuador, Brasil, Colombia and number of African countries. We did not have one! We asked the Immigrations person if we could just go get a vaccination, he indicated that the vaccination needed have been done 10 days ago and did not let us in the country. We were given no options and our airline was given strict instructions to either send us back to Peru, or to the USA (which is where we live.) We contacted Arenal Kioro immediately and provided them proof of our terrible story. They requested scans of our immigration papers, passports stamped from Costa Rica - Peru - Costa Rica, etc. All the evidence was sent, and they refunded us NOTHING. So, why did they request the proof? We would have understood if they had kept a percentage of the total payment (which was pre-payed) but, no, they refunded $0. We are sure this must be a beautiful hotel, and we were so excited about our short romantic trip, but did not get there. What was most hurtful, was their unwillingness to work with us. We would have taken 50% back and would have rescheduled our vacation for another time. Now, we will never go.